U.S. patent application number 15/546905 was filed with the patent office on 2018-01-04 for multilayer film.
This patent application is currently assigned to KURARAY CO., LTD.. The applicant listed for this patent is KURARAY CO., LTD.. Invention is credited to Hiroshi KAWAKITA, Kirihiro NAKANO, Hideaki TAKEDA.
Application Number | 20180002573 15/546905 |
Document ID | / |
Family ID | 56543473 |
Filed Date | 2018-01-04 |
United States Patent
Application |
20180002573 |
Kind Code |
A1 |
KAWAKITA; Hiroshi ; et
al. |
January 4, 2018 |
MULTILAYER FILM
Abstract
Provided are a multilayer film, a method for producing the
multilayer film, and a method for producing a molded body. The
multilayer film has excellent three-dimensional overlaying
formability and adhesiveness after being formed; can easily be used
when being bonded to an adherend; maintains adhesive strength.
Specifically, the multilayer film has: an adhesive layer comprising
a thermoplastic polymer composition containing a thermoplastic
elastomer (A) which is a block copolymer or a hydrogenated product
thereof having a polymer block (a1) containing aromatic vinyl
compound units and having a polymer block (a2) containing
conjugated diene compound units; and a base layer comprising an
amorphous resin which has a modulus of elasticity of 2 to 600 MPa
at an arbitrary temperature of 110 to 160.degree. C. The tensile
elongation at break of the multilayer film at a temperature
5.degree. C. lower than the glass transition temperature of the
amorphous resin is at least 160%.
Inventors: |
KAWAKITA; Hiroshi;
(Tsukuba-shi, JP) ; NAKANO; Kirihiro;
(Tsukuba-shi, JP) ; TAKEDA; Hideaki; (Tsukuba-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KURARAY CO., LTD. |
Kurashiki-shi |
|
JP |
|
|
Assignee: |
KURARAY CO., LTD.
Kurashiki-shi
JP
|
Family ID: |
56543473 |
Appl. No.: |
15/546905 |
Filed: |
January 28, 2016 |
PCT Filed: |
January 28, 2016 |
PCT NO: |
PCT/JP2016/052489 |
371 Date: |
July 27, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 27/08 20130101;
C09J 153/025 20130101; C09J 2301/40 20200801; C09J 7/20 20180101;
B29C 48/21 20190201; B29K 2023/12 20130101; C09J 2453/00 20130101;
B29K 2021/003 20130101; C09J 123/10 20130101; C09J 7/24 20180101;
B32B 2274/00 20130101; C09J 2433/006 20130101; B29K 2025/00
20130101; B29K 2009/00 20130101; C09J 129/14 20130101; C09J 2451/00
20130101; B29C 65/48 20130101; B29L 2009/00 20130101; C09J 153/02
20130101; B32B 27/308 20130101; B29C 51/10 20130101; B32B 27/302
20130101; C09J 2453/006 20130101 |
International
Class: |
C09J 7/02 20060101
C09J007/02; B29C 65/48 20060101 B29C065/48; B29C 47/06 20060101
B29C047/06; B32B 27/30 20060101 B32B027/30; B32B 27/08 20060101
B32B027/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2015 |
JP |
2015-014313 |
Claims
1: A multilayer film comprising: an adhesive layer comprising a
thermoplastic polymer composition comprising a thermoplastic
elastomer (A), which is a block copolymer or a hydrogenated block
copolymer having a polymer block (a1) comprising an aromatic vinyl
compound unit and a polymer block (a2) comprising a conjugated
diene compound unit; and a base layer comprising an amorphous resin
having an elastic modulus of 2 to 600 MPa at an arbitrary
temperature of 110.degree. C. to 160.degree. C., wherein elongation
at break of the multilayer film at a temperature lower by 5.degree.
C. than a glass transition temperature of the amorphous resin is at
least 160%.
2: The multilayer film according to claim 1, wherein the polymer
block (a2) comprising the conjugated diene compound unit is a
polymer block comprising an isoprene unit, a butadiene unit or
isoprene/butadiene units in which 1,2 bonds and 3,4 bonds together
constitute at least 40 mol % of the bonds, and the thermoplastic
polymer composition comprises an adhesion imparting component (B)
that is a polyvinyl acetal resin (B1) and/or a polar
group-containing polypropylene resin (B2) in an amount of 10 to 100
mass parts per 100 mass parts of the thermoplastic elastomer
(A).
3: The multilayer film according to claim 1, wherein the amorphous
resin in the base layer comprises an acrylic-based resin comprising
a methacrylic-based resin (F) and an elastic body (R), a structural
unit derived from methyl methacrylate constitutes at least 80 mass
% of the methacrylic-based resin (F), and an amount of the
methacrylic-based resin (F) is 10 to 99 mass parts and an amount of
the elastic body (R) is 90 to 1 mass parts per 100 mass parts of a
total of the methacrylic-based resin (F) and the elastic body
(R).
4: The multilayer film according to claim 3, wherein the elastic
body (R) has in a molecule one or more methacrylic ester polymer
blocks (g1) each comprising a structural unit derived from a
methacrylic ester and one or more acrylic ester polymer blocks (g2)
each comprising a structural unit derived from an acrylic ester,
and also has the methacrylic ester polymer block (g1) in a ratio of
10 to 80 mass % and the acrylic ester polymer block (g2) in a ratio
of 90 to 20 mass %, and given Mw(F) as weight-average molecular
weight of the methacrylic-based resin (F), Mw(g1-total) as
weight-average molecular weight per molecule of the methacrylic
ester polymer block (g1) contained in the block copolymer (G), and
Mw(g2-total) as weight-average molecular weight per molecule of the
acrylic ester polymer block (g2) contained in the block copolymer
(G), then 0.3.ltoreq.Mw(F)/Mw(g1-total).ltoreq.4.0, and (1)
30,000.ltoreq.Mw(g2-total).ltoreq.140,000 (2) are satisfied.
5. The multilayer film according to claim 4, wherein structural
units derived from an acrylic acid alkyl ester constitute 50 to 90
mass % of the acrylic ester polymer block (g2) and structural units
derived from a (meth)acrylic acid aromatic ester constitute 50 to
10 mass % of the acrylic ester polymer block (g2).
6. The multilayer film according to claim 3, wherein the elastic
body (R) is a multilayer structure (E) having at least an outer
layer (e1) of which methyl methacrylate constitutes at least 80
mass %, and an inner layer (e2) of which an acrylic acid alkyl
ester constitutes 70 to 99.8 mass % and a crosslinkable monomer
constitutes 0.2 to 30 mass %.
7: The multilayer film according claim 1, wherein the thermoplastic
polymer composition further contains comprises a polar
group-containing polyolefin-based copolymer (C).
8: The multilayer film according to claim 1, which is a decorative
film.
9: The multilayer film according to claim 1, wherein the base layer
is obtained by mixing 1 to 10 mass parts of a colorant per 100 mass
parts of the amorphous resin.
10: The multilayer film according to claim 1, wherein a ratio of
thickness of the base layer to thickness of the adhesive layer is
in a range of 0.2 to 5.
11: The multilayer film according to claim 1, the total thickness
of which is less than 1,000 .mu.m.
12: The multilayer film according to claim 1, wherein a pencil
hardness on the base layer side is at least HB.
13: A method for manufacturing the multilayer film of claim 1,
comprising co-extruding an amorphous resin with an elastic modulus
of 2 to 600 MPa at an arbitrary temperature of 110.degree. C. to
160.degree. C. together with a thermoplastic polymer composition
comprising a thermoplastic elastomer (A) that is a block copolymer
or a hydrogenated block copolymer having a polymer block (a1)
comprising an aromatic vinyl compound unit and a polymer block (a2)
comprising; a conjugated diene compound unit.
14: A molded body comprising the multilayer film of claim 1 and an
adherend.
15: A method for manufacturing a molded body, the method
comprising: enclosing the multilayer film of claim 1 and an
adherend in a chamber box; reducing pressure inside the chamber
box; bisecting the chamber box by the multilayer film, and
increasing the pressure in the chamber box not having the adherend
higher than the pressure in the chamber box having the adherend, to
thereby overlay the adherend with the multilayer film.
16: The method according to claim 15, further comprising softening
the multilayer film by heating to within a range of 110.degree. C.
to 160.degree. C.
Description
TECHNICAL FIELD
[0001] The present invention relates to a multilayer film having an
adhesive layer.
BACKGROUND ART
[0002] Components made of ceramics, metal, synthetic resin and the
like with excellent durability, heat resistance and mechanical
strength are widely used for a variety of applications including
household appliances, electronic components, mechanical components,
automotive components and the like. In applications such as
appliance exteriors, wallpapers and automobile interiors,
decorative films are often bonded to these materials to give a
pattern such as a wood grain pattern, to provide a design feature
such as a metallic tone or piano black tone, or to impart a
function such as scratch resistance or weather resistance.
[0003] One method that is used for bonding decorative films to
adherends having three-dimensional shapes is, for example, film
insert molding, in which injection molding is performed with a
decorative film set in a mold. In this method the decorative film
must be press shaped in advance to fit the shape of the mold, and
the method is also hard to apply to adherends made of metal,
heat-curing resins and the like. Decorative methods that avoid this
problem include vacuum molding methods such as three-dimensional
surface decorative molding, but these face issues of productivity
because they require adhesives.
[0004] To solve these problems, Patent Literature 1 for example
proposes a film consisting of a thermoplastic polymer composition
and having an adhesive property, and a method for manufacturing a
molded body by using this film for insert molding. However, the
molded body having this film has extremely poor conformability to
three-dimensional shapes in vacuum molding, and breaks and wrinkles
have occurred among other problems
[0005] Patent Literature 2 for example proposes a multilayer film
having a film composed of a methacrylate-based resin composition
containing a block copolymer and a methacrylate-based resin and a
film composed of an acrylate-based block copolymer, in which the
toughness of the acrylic film is reportedly improved by including
the block copolymer. However, this multilayer film has had a
problem of poor adhesiveness to non-polar resins.
[0006] Patent Literature 3 proposes an acrylic-based resin film
including a core-shell particle obtained by copolymerizing an alkyl
methacrylate ester and an alkyl acrylate ester in the presence of a
crosslinked particle of an alkyl acrylate ester polymer, wherein
the core-shell particle is compounded in a methacrylic-based
resin.
[0007] However, there is demand for an acrylic-based resin film
that has even greater transparency, surface hardness, surface
smoothness and extensibility and undergoes little whitening when
healed. In particular, there is demand for a film that is easy to
mold and has good overlaying formability on articles with
three-dimensionally curved surfaces.
CITATION LIST
Patent Literature
[0008] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 2014-168940
[0009] Patent Literature 2: Japanese Unexamined Patent Application
Publication No. 2012-213911
[0010] Patent Literature 3: Japanese Examined Patent Application
Publication No. S56-27378
SUMMARY OF INVENTION
Technical Problem
[0011] It is an object of the present invention to provide a
multilayer film having an adhesive layer, capable of bonding easily
to an adherend without breakage or wrinkles at a wide range of
temperatures, and suitable for vacuum molding with excellent
three-dimensional overlaying formability and adhesiveness after
being formed into a three-dimensional overlay, together with a
method for manufacturing the multilayer film and a method for
manufacturing a molded body using the multilayer film.
Solution to Problem
[0012] In the present invention, this object is achieved by
providing the following. [0013] [1] A multilayer film including: an
adhesive layer formed of a thermoplastic polymer composition
containing a thermoplastic elastomer (A), which is a block
copolymer or hydrogenated block copolymer having a polymer block
(a1) containing an aromatic vinyl compound unit and a polymer block
(a2) containing a conjugated diene compound unit; and a base layer
formed of an amorphous resin having an elastic modulus of 2 to 600
MPa at an arbitrary temperature of 110.degree. C. to 160.degree.
C., wherein elongation at break of the multilayer film at a
temperature lower by 5.degree. C. than glass transition temperature
of the amorphous resin is at least 160%. [0014] [2] The multilayer
film according to [1], wherein the polymer block (a2) containing
the conjugated diene compound unit is a polymer block communing
isoprene units, butadiene units or isoprene/butadiene in which 1,2
bonds and 3,4 bonds together constitute at least 40 mol % of the
bonds, and
[0015] the thermoplastic polymer composition contains an adhesion
imparting component (B) that is a polyvinyl acetal resin (B1)
and/or a polar group-containing polypropylene-based resin (B2) in
an amount of 10 to 100 mass parts per 100 mass parts of the
thermoplastic elastomer (A). [0016] [3] The multilayer film
according to [1] or [2], wherein the amorphous resin in the base
layer includes an acrylic-based resin containing a
methacrylic-based resin (F) and an elastic body (R),
[0017] a structural unit derived from methyl methacrylate
constitutes at least 80 mass % of the methacrylic-based resin (F),
and
[0018] an amount of the methacrylic-based resin (F) is 10 to 99
mass parts and the amount of the elastic body (R) is 90 to 1 mass
parts of a total of the methacrylic-based resin (F) and the elastic
body (R). [0019] [4] The multilayer film according to [3], wherein
the elastic body (R) has in a molecule one or more methacrylic
ester polymer blocks (g1) each containing a structural unit derived
from a methacrylic ester and one or more acrylic ester polymer
blocks (g2) each containing a structural unit derived from an
acrylic ester, and also has the methacrylic ester polymer block
(g1) in a ratio of 10 to 80 mass % and the acrylic ester polymer
block (g2) in a ratio of 90 to 20 mass %, and
[0020] given Mw(F) as weigh-average molecular weight of the
methacrylic-based resin (F), Mw(g1-total) as weight-average
molecular weight per molecule of the methacrylic ester polymer
block (g1) contained in the block copolymer (G), and Mw(g2-total)
as weight-average molecular weight per molecule of the acrylic
ester polymer block (g2) contained in the block copolymer (G), then
[0021] (1) 0.3.ltoreq.Mw(F)/Mw(g1-total).ltoreq.4.0, and [0022] (2)
30,000.ltoreq.Mw(g2-total).ltoreq.140,000 are satisfied.
[0023] [5] The multilayer film according to [4], wherein structural
units derived from an acrylic alkyl ester constitute 50 to 90 mass
% of the acrylic ester polymer block (g2) and structural units
derived from a (meth)acrylic acid aromatic ester constitute 50 to
10 mass % of the acrylic ester polymer block (g2).
[0024] [6] The multilayer film according to [3], wherein the
elastic body (R) is a multilayer structure (E) having at least an
outer layer (e1) of which methyl methacrylate constitutes at least
80 mass %, and an inner layer (e2) of which an acrylic acid alkyl
ester constitutes 70 to 99.8 mass % and a crosslinkable monomer
constitutes 0.2 to 30 mass %
[0025] [7] The multilayer film according to any [1] to [6], wherein
the thermoplastic polymer composition further contain a polar
group-containing polyolefinic-based copolymer (C) (which is
different from the polar group-containing polypropylene-based resin
(B2)).
[0026] [8] The multilayer film according to any of [1] to [7],
which is a decorative film.
[0027] [9] The multilayer film according to any of [1] to [8],
wherein the base layer is obtained by mixing 1 to 10 mass parts of
a colorant per 100 mass parts of the amorphous resin.
[0028] [10] The multilayer film according to any [1] to [9],
wherein a ratio of thickness of the base layer to thickness of the
adhesive layer is in a range of 0.2 to 5.
[0029] [11] The multilayer film according to any [1] to [10], the
total thickness of which is less than 1,000 .mu.m.
[0030] [12] The multilayer film according to any of [1] to [11],
wherein pencil hardness on the base layer side is at least HB.
[0031] [13] A method for manufacturing the multilayer film of [1]
by co-extruding an amorphous resin with an elastic modulus of 2 to
600 MPa at an arbitrary temperature of 110.degree. C. to
160.degree. C. together with a thermoplastic polymer composition
containing a thermoplastic elastomer (A) that is a block copolymer
or a hydrogenated block copolymer having a polymer block (a1)
containing an aromatic vinyl compound unit and a polymer block (a2)
containing a conjugated diene compound unit.
[0032] [14] A molded body including a multilayer film of any of [1]
to [12] and an adherend.
[0033] [15] A method for manufacturing a molded body, the method
including:
[0034] a step of enclosing the multilayer film of any of [1] to
[12] and an adherend in a chamber box;
[0035] a step of reducing pressure inside the chamber box;
[0036] a step of bisecting the chamber box by the multilayer film;
and
[0037] a step of increasing the pressure in the chamber box not
having the adherend higher than pressure in the chamber box having
the adherend, to thereby overlay the adherend with the multilayer
film.
[0038] [16] The method of manufacturing a molded body of [15],
further including a step of softening the multilayer film by
heating to within a range of 110.degree. C. to 160.degree. C.
Advantageous Effects of Invention
[0039] Because the multilayer film of the present invention has
excellent three-dimensional overlaying formability and adhesiveness
after being formed into a three-dimensional overlay, and can easily
bond to an adherend without breakage or wrinkles at a wide range of
temperatures, it is suited to decorating products that require
design features.
DESCRIPTION OF EMBODIMENTS
[0040] The multilayer film of the present invention has an adhesive
layer and a base layer. The thermoplastic polymer composition
constituting the adhesive layer contains a thermoplastic elastomer
(A). The thermoplastic elastomer (A) consists of a block copolymer
or a hydrogenated copolymer having a polymer block (a1) containing
an aromatic vinyl compound unit and a polymer block (a2) containing
a conjugated diene compound unit.
[0041] Examples of the aromatic vinyl compound constituting the
polymer block (a1) containing an aromatic vinyl compound unit
include styrene, .alpha.-methylstyrene, 2-methylstyrene,
3-methylstyrene, 4-methylstyrere, 4-propylstyrene,
4-cyclohexylstyrene, 4-dodecystyrene, 2-ethyl-4-benzylstyrene,
4-(phenylbuytyl)styrene, 1-vinylnaphthalene and 2-vinylnaphthalene,
and one or two or more of these may constitute the polymer block.
Of these, styrene, .alpha.-methylstyrene and 4-methylstyrene are
desirable from the standpoint of flowability.
[0042] The polymer block (a1) containing the aromatic vinyl
compound unit contains the aromatic vinyl compound unit in the
amount of preferably at least 80 mass %, or more preferably at
least 90 mass %, or still more preferably at least 95 mass %. The
polymer block (a1) containing the aromatic vinyl compound unit may
also have another copolymerizable monomer unit in addition to the
aromatic vinyl compound unit. Examples of this other
copolymerizable monomer include 1-butene, pentene, hexene,
butadiene, isoprene and methyl vinyl ether. When the polymer block
(a1) containing the aromatic vinyl compound unit also contains
another copolymeriable monomer unit, the ratio thereof is
preferably not more than 20 mass %, or more preferably not more
than 10 mass %, or still more preferably not more than 5 mass % of
the total amount of the- aromatic -vinyl compound unit and the
other copolymerizable monomer unit.
[0043] Examples of the conjugated diene compound constituting the
polymer block (a2) containing a conjugated diene compound unit
include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene,
1,3-pentadiene and 1,3-hexadiene, and one or two or more of these
mas constitute the polymer block. Preferably the block is made up
of structural units derived from butadiene and/or isoprene, or
especially preferably of structural units derived from butadiene
and isoprene.
[0044] The form of binding of the conjugated diene compound units
is not particularly limited, and for example it may be 1,2 binding
and 1,4 binding in the case of butadiene, or 1,2 binding 3,4
binding and 1,4 binding in the case of isoprene. In the polymer
block (a2) consisting of the conjugated diene compound units, the
ratio of the total amount of 1,2 binding and 3,4 binding as a
percentage of the total amount of 1,2 binding 3,4 binding and 1,4
binding is preferably in the range of 1 to 99 mol %, or more
preferably 35 to 98 mol %, still more preferably 40 to 90 mol %, or
especially preferably 50 to 80 mol %. The relative amount of 1,2
binding, 3,4 binding and 1,4 binding can be calculated from the
integral values of the peaks in the range of 4.2 to 5.0 ppm
attributable to 1,2 bonding and 3,4 binding and the integral value
of the peak in the range of 5.0 to 5.45 ppm attributable to 1,4
binding in the .sup.1H-NMR spectrum.
[0045] The polymer block (a2) containing a conjugated diene
compound unit includes preferably at least 80 mass %, or more
preferably at least 90 mass %, or still more preferably at least 95
mass % of conjugated diene compound units (equivalent raw material
charged amounts in all cases). The polymer block containing a
conjugated diene compound unit may also have another
copolymerizable monomer unit in addition to the conjugated diene
compound unit. Examples of this other copolymerizable monomer
include styrene, .alpha.-methylstyrene and 4-methylstyrene. When
another copolymerizable monomer unit is included, the ratio thereof
is preferably not more than 20 mass %, or more preferably not more
than 10 mass %, or still more preferably not more than 5 mass % of
the total of the conjugated diene compound unit and the other
copolymerizable monomer unit.
[0046] The form of binding of the polymer block (a1) containing an
aromatic vinyl compound unit and the polymer block (a2) containing
a conjugated diene compound unit in the thermoplastic elastomer (A)
is not particularly limited, and may be linear, branched, radial or
a combination of two or more of these binding forms. Of these, a
linear binding form is preferred for ease of manufacture. Examples
of linear binding forms include a diblock copolymer represented as
a1-a2, a tri block copolymer represented as a1-a2-a1 or a2-a1-a2, a
tetrablock copolymer represented as a1-a2-a1-a2, a pentablock
copolymer represented as a1-a2-a1-a2-a1 or a2-a1-a2-a1-a2, an
(a1-a2)nX copolymer (in which X represents a coupling residue, and
n represents an integer of 2 or greater), and mixtures of these. Of
these, a triblock copolymer is preferred because it is easy to
manufacture and has superior extensibility and adhesiveness, and a
triblock copolymer represented by a1-a2-a1 is especially
preferred
[0047] From the standpoint of heat resistance and weather
resistance, all or some of the polymer blocks (a2) containing the
conjugated diene compound are preferably hydrogenated in the
thermoplastic elastomer (A). The hydrogenation rate of the polymer
blocks (a2) containing the conjugated diene compound is preferably
at least 80%, or more preferably at least 90%. The hydrogenation
rate is a value obtained by measuring the iodine value of the block
copolymer before and after the hydrogenation reaction.
[0048] In the thermoplastic elastomer (A), the content of the
polymer block (a1) containing the aromatic vinyl compound unit is
preferably in the range of 5 to 75 mass %, or more preferably 5 to
60 mass %, or still more preferably 10 to 40 mass %, of the total
of the thermoplastic elastomer (A) from the standpoint of
flexibility, extensibility and adhesiveness. The weight-average
molecular weight of the thermoplastic elastomer (A) is preferably
in the range of 30,000 to 500,000, or more preferably 60,000 to
200,000 still more preferably 80,000 to 180,000 from the standpoint
of extensibility, adhesiveness, and forming processability. The
weight-average molecular weight here is the polystyrene equivalent
value as determined by gel permeation chromatography (GPC). One
kind of the thermoplastic elastomer (A) may be used alone, or a
combination of two or more kinds may be used. A combination of a
medium-molecular-weight elastomer with a weight-average molecular
weight of 50,000 to 150,000 with a high-molecular-weight elastomer
with a weight-average molecular weight of 150,000 to 300,000 is
desirable for obtaining a good balance of extensibility,
adhesiveness and forming processability. The mass ratio of the
medium-molecular-weight elastomer to the high-molecular-weight
elastomer is preferably in the range of 10/90 to 90/10, or more
preferably 20/80 to 75/25, or still more preferably 20/80 to
55/45.
[0049] The method for manufacturing the thermoplastic elastomer (A)
is not particularly limited, and it can be manufactured for example
by anionic polymerization. Specifically, it can be manufactured by
(i) a method in which the aromatic vinyl compound and conjugated
diene compound are sequentially polymerized using an alkyl lithium
compound as an initiator; (ii) a method in which the aromatic vinyl
compound and conjugated diene compound are sequentially polymerized
using an alkyl lithium compound as an initiator, after which a
coupling agent is added to perform coupling; and (iii) a method in
which the conjugated diene compound and the aromatic vinyl compound
are sequentially polymerized using a dilithium compound as an
initiator.
[0050] The alkyl lithium compound in (i) and (ii) above may be
methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium,
tert-butyl lithium or pentyl lithium for example. The coupling
agent in (ii) above may be dichloromethane, dibromomethane,
dichloroethane, dibromoethane of dibromobenzene for example. The
dilithium compound in (iii) above may be naphthalene dilithium or
dilithiohexylbenzene for example.
[0051] The amounts of these alkyl lithium compounds, dilithium
compounds and other initiators and coupling agents that are used
may be determined according to weight-average molecular weight of
the target thermoplastic elastomer (A), but normally the amount of
the initiator is in the range of 0.01 to 0.2 mass parts and the
amount of the coupling agent is in the range of 0.001 to 0.8 mass
parts per 100 mass parts of the combined aromatic vinyl compound
and conjugated diene compound. The anionic polymerization described
above is preferably performed in the presence of a solvent. The
solvent may be any that is inactive with respect to the initiator
and does not adversely affect polymerization, without any
particular limitations, and examples include saturated aliphatic
hydrocarbons such as hexane, heptane, octane and decane; and
aromatic hydrocarbons such as toluene, benzene and xylene.
Polymerization is preferably performed for 0.5 to 50 hours within a
temperature range of 0.degree. C. to 80.degree. C.
[0052] The ratios of 1.2 binding and 3.4 binding in the
thermoplastic elastomer (A) can be increased by adding an organic
Lewis base during anionic polymerization, and the ratios of 1,2
binding and 3,4 binding can be easily controlled by varying the
added amount of this organic Lewis base. Examples of the organic
Lewis base include esters such as ethyl acetate; amines such as
triethylamine, N,N,N',N'-tetramethylethylenediamine and
N-methylmorpholine; nitrogen-containing heterocyclic aromatic
compounds such as pyridine; amides such as dimethylacetamide;
ethers such as dimethyl ether, diethyl ether, tetrahydrofuran and
dioxane; glycol ethers such as ethylene glycol dimethyl ether and
diethylene glycol dimethyl ether; sulfoxides such as dimethyl
sulfoxide; and ketones such as acetone and methyl ethyl ketone.
[0053] Following polymerization by the methods described above, the
reaction solution can be poured into a weak solution for the block
copolymer to coagulate the block copolymer contained in the
reaction solution, or else the reaction liquid can be poured
together with steam into hot water to remote the solvent
azeotropically (steam stripping), and then dried to isolate the
non-hydrogenated thermoplastic elastomer (A). This non-hydrogenated
thermoplastic elastomer (A) can then be subjected to a
hydrogenation reaction to obtain a hydrogenated thermoplastic
elastomer (A). In the hydrogenation reaction, hydrogen is reacted
in the presence of a hydrogenation catalyst either with a solution
of the non-hydrogenated thermoplastic elastomer (A) and a solvent
that is inactive with respect the reaction and the hydrogenation
catalyst or with the non-hydrogenated thermoplastic elastomer (A)
which has not been isolated from the reaction solution. Examples of
the hydrogenation catalyst include Raney nickel; unhindered
catalysts including metals such as Pt, Pd, Ru Rh and Ni carried on
carriers of carbon, alumina, diatomaceous earth and the like;
Ziegler catalysts formed from a combination of a transition metal
compound with an alkyl aluminum compound, alkyl lithium compound or
the like; and metallocene catalysts. The hydrogenation reaction can
normally be performed under conditions of hydrogen pressure 0.1 to
20 MPa, reaction temperature 20.degree. C. to 250.degree. C., and
reaction time 0.1 to 100 hours. The hydrogenated thermoplastic
elastomer (A) can also be isolated either by pouring the
hydrogenation reaction solution into a weak solvent such as
methanol to coagulate it, or by pouring the hydrogenation reaction
solution together with steam into hot water to remove the solvent
azeotropically (steam stripping), and then drying the solution.
[0054] The thermoplastic polymer composition may also contain an
adhesion imparting component (B). The adhesion imparting component
(B) is preferably a polyvinyl acetal resin (B1) and/or a polar
group-containing polypropylene-based resin (B2), or more preferably
a polyvinyl acetal resin (B1) and/or a carboxylic acid-modified
polypropylene-based resin.
[0055] The content of the adhesion imparting component (B) is
preferably in the range of 10 to 100 mass parts per 100 mass parts
of the thermoplastic elastomer (A). The content is more preferably
at least 12 mass parts, or still more preferably at least 15 mass
parts, and more preferably not more than 70 mass parts, or still
more preferably not more than 50 mass parts. Thus, the content of
the adhesion imparting component (B) is preferably 10 to 70 mass
parts, or more preferably 12 to 70 mass parts, or still more
preferably 15 to 70 mass parts, or yet more preferably 15 to 50
mass parts, or especially preferably 15 to 45 mass parts per 1.00
mass parts of the thermoplastic elastomer (A). If the content of
the adhesion imparting component (B) is less than 1.0 mass parts,
adhesiveness tends to be less, while if it exceeds 100 mass parts
the flexibility and adhesiveness of the thermoplastic polymer
composition tend to be less.
[0056] The polyvinyl acetal resin (B1) normally has a repeating
unit represented by Formula (1) below.
##STR00001##
[0057] In Formula (1) above, "n" represents the number of types of
aldehyde used in the acetalization reaction. R1, R2, . . . , Rn
represent hydrogen atoms or alkyl residues of the aldehydes used in
the acetalization reaction, and k(1), k(2), . . . , k(n) represent
the proportions (substance ratios) of each constituent unit in
square brackets, "l" represents the proportion (substance ratio) of
vinyl alcohol units, and "m" represents the proportion (substance
ratio) of vinyl acetal units. However, k(1)+k(2)+ . . .
+k(n)+1+m=1, and any of k(1), k(2), . . . , k(n), "l" and "m" may
be zero. Each repeating unit is not particularly limited to the
sequence order given above, and the units may be in a random
sequence, or in a block sequence or tapered sequence.
[0058] The polyvinyl acetal resin (B1) is obtained for example by
reacting a polyvinyl alcohol with an aldehyde. The average degree
of polymerization of the polyvinyl alcohol used in manufacturing
the polyvinyl acetal resin (B1) is preferably 100 to 4,000 or more
preferably 100 to 3,000 or still more preferably 100 to 2,000, or
especially preferably 250 to 2,000. If the average degree of
polymerization of the polyvinyl alcohol is at least 100 the
polyvinyl acetal resin (B1) has good productivity and handling
properties, while if it is not more than 4,000 the melt viscosity
does not become too high during melt kneading, and the
thermoplastic polymer composition is easier to manufacture. The
average degree of polymerization of the polyvinyl alcohol here is a
value measured in accordance with JIS K 6726, and is determined
from the intrinsic viscosity as measured in water at 30.degree. C.
after the polyvinyl alcohol has been re-saponified and
purified.
[0059] There are no particular limitations on the method of
manufacturing the polyvinyl alcohol, which may be produced for
example by saponifying polyvinyl acetate or the like with an
alkali, acid, ammonia water or the like. A commercial product may
also be used. An example of a commercial product is the Kuraray
Poval series manufactured by Kuraray Co., Ltd. The polyvinyl
alcohol may have been completely saponified or partly saponified.
From the standpoint of compatibility and stability, the degree of
saponification is preferably at least 80 mol %, or more preferably
at least 90 mol %, or still more preferably at least 95 mol %.
[0060] A vinyl alcohol such as an ethylene-vinyl alcohol copolymer
or partially saponified ethylene-vinyl alcohol copolymer, a
copolymer of monomer copolymerizable with such a vinyl alcohol, or
a modified polyvinyl alcohol with carboxylic acid or the like
introduced into a part thereof may be used as the polyvinyl
alcohol. One of these kinds of polyvinyl alcohol alone or a
combination of two or more kinds may be used.
[0061] The aldehyde used in manufacturing the polyvinyl acetal
resin (B1) is not particularly limited. Examples include
formaldehyde (including paraformaldehyde), acetaldehyde (including
paraacetaldehyde), propionaldehyde, n-butyraldehyde,
isobutyraldehyde, pentanal, hexanal, heptanal, n-octanal,
2-ethylhexylaldehyde, cyclohexanecarbaldehyde, furfural, glyoxal
glutaraldehyde, benzaldehyde, 2-methylbenzaldehyde,
3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxbenzaldehyde,
m-hydroxybenzaldehyde, phenylacetaldehyde and
.beta.-phenylpropionaldehyde, and one of these alone or a
combination of two or more may be used. Of these aldehydes,
butyraldehyde is preferred and n-butyraldehyde is especially
preferred from the standpoint of ease of manufacture.
[0062] The polyvinyl acetal resin (B1) is preferably a polyvinyl
acetal resin (B1) obtained by acetalizing a polyvinyl alcohol with
n-butyraldehyde. Of the acetal units in the polyvinyl acetal resin
(B1), the ratio of butyral traits is preferably at least 0.8, or
more preferably at least 0.9, or still more preferably at least
0.95.
[0063] The degree of acetalization of the polyvinyl acetal resin
(B1) used in the present invention is in the range of preferably 55
to 88 mol %, or more preferably 60 to 88 mol %, or still more
preferably 70 to 88 mol %, or especially preferably 75 to 85 mol %.
A polyvinyl acetal resin (B1) with a degree of acetalization of at
least 55 mol % is inexpensive to manufacture and easy to obtain,
and has good melt processability. On the other hand, a polyvinyl
acetal resin (B1) with a degree of acetalization of not more than
88 mol % is extremely easy to manufacture, and economical because
the acetalization reaction is not time-consuming. Adhesiveness is
excellent if the degree of acetalization of the polyvinyl acetal
resin (B1) is not more than 88mol %, while if it is at least 55 mol
% the resin has good affinity and compatibility with the
thermoplastic elastomer (A), giving the resulting, thermoplastic
polymer composition both excellent extensibility and good adhesive
strength.
[0064] The degree of acetalization (mol %) of the polyvinyl acetal
resin (B1) is defined by the following formula.
Degree of acetalization (mol %)={k(1)+k(2)+ . . .
+k(n)}.times.2/{{k(1)+k(2)+ . . . +k(n)}.times.2+1+m}.times.100
[0065] The degree of acetalization of the polyvinyl acetal resin
(B1) is determined by the method described in JIS K 6728
(1977).
[0066] From the standpoint of affinity with the thermoplastic
elastomer (A), the content "1" of vinyl alcohol units in the
polyvinyl acetal resin (B1) is in the range of preferably 12 to 45
mol %, or more preferably 12 to 40 mol %, while the content of
vinyl acetate units is in the range of preferably 0 to 5 mol %, or
more preferably 0 to 3 mol %.
[0067] The reaction between the polyvinyl alcohol and the aldehyde
(acetalization reaction) mas be performed by known methods.
Examples include a water-mediated method in which an acetalization
reaction is performed on an aldehyde and an aqueous solution of a
polyvinyl alcohol in the presence of an acid catalyst to
precipitate particles of the polyvinyl acetal resin (B1) and a
solvent-mediated method in which a polvinyl alcohol is dispersed in
an organic solvent and subjected to an acetalization reaction with
an aldehyde in the presence of an acid catalyst, after which water
(a poor solvent for the polyvinyl acetal resin (B1)) or the like is
mixed with the resulting reaction mixture to precipitate the
polyvinyl acetal resin (B1). The acid catalyst is not particularly
limited, and examples include organic acids such as acetic acid and
p-toluenesulfonic acid; inorganic acids such as nitric acid,
sulfuric acid and hydrochloric acid; gases such as carbon dioxide
that are acidic in aqueous solution; and solid acid catalysts such
as cation exchange resins and metal oxides.
[0068] A slurry consisting of a reaction mixture of a polyvinyl
alcohol and an aldehyde prepared by a water-mediated method,
solvent-mediated method or the like is normally acidic, so the pH
of this slurry is preferably adjusted to the range of 5 to 9, or
more preferably 6 to 8 in order to reduce the effects on subsequent
reactions. Methods of adjusting the pH include repeated water
washing of the slurry; addition of a neutralizing agent to the
slurry; and addition of an alkylene oxide or the like so the
slurry. Examples of the compound used to adjust the pH include
alkali metal hydroxides such as sodium hydroxide and potassium
hydroxide; alkali metal acetates such as sodium acetate; alkali
metal carbonates such as sodium carbonate and potassium carbonate;
alkali metal hydrogencarbonates such as sodium hydrogencarbonate;
and ammonia and aqueous ammonia solutions. Examples of alkylene
oxides include ethylene oxide and propylene oxide, and a glycidyl
ether such as ethylene glycol diglycidyl ether may also be
used.
[0069] There are no particular limits on the methods for removing
the salts produced by pH adjustment, the residue from the reaction
with the aldehyde and the like. Preferably when the polyvinyl
acetal resin (B1) is processed into a powder, granules or pellets
it is deaerated under reduced pressure to reduce the reaction
residue, moisture content and the like.
[0070] From the standpoint of adhesiveness, the polar
group-containing polypropylene-based resin (B2) is preferably a
polypropylene containing a carboxyl group as a polar group, or in
other words a carboxylic acid-modified polypropylene-based resin,
and more preferably it is a maleic acid-modified
polypropylene-based resin or maleic anhydride-modified
polypropylene-based resin. The polar group of the polar
group-containing polypropylene-based resin (B2) may be a
(meth)acryloyloxy group; a hydroxyl group; an amido group; a
halogen atom such as a chlorine atom; a carboxyl group; or an acid
anhydride group for example.
[0071] The method for manufacturing the polar group-containing
polypropylene-based resin (B2) is not particularly limited, and it
may be obtained by random copolymerizing, block copolymerizing or
graft copolymerizing propylene with a polar group-containing
copolymerizable monomer by known methods, or by oxidizing or
chlorinating a polypropylene-based based resin by known methods. Of
these methods, random copolymerization and graft copolymerization
are preferred because they allow precise control of the molecular
weight distribution, and graft copolymerization is especially
preferred.
[0072] Examples of the polar group-containing copolymerizable
monomer include vinyl acetate, vinyl chloride, ethylene oxide,
propylene oxide, acrylamide, unsaturated carboxylic acids and
esters and anhydrides thereof. Of these, an unsaturated carboxylic
acid or ester or anhydride thereof is preferred. Examples of
unsaturated carboxylic acids and their esters and anhydrides
include (meth)acrylic acid, (meth)acrylic acid esters, maleic acid,
maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride,
himic acid and himic anhydride. Of these, maleic acid or maleic
anhydride is especially preferred from the standpoint of
adhesiveness. One of these polar group-containing copolymerizable
monomers may be used alone, or two or more may be combined.
[0073] Examples of the (meth)acrylic esters given as examples of
the polar group-containing copolymerizable monomer include acrylic
acid alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl
acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate,
n-hexyl acrylate, isohexyl acrylate, n-octyl acrylate, isooctyl
acrylate and 2-ethylhexyl acrylate; and methacrylate acid alkyl
esters such as methyl methacrylate, ethyl methacrylate, n-propyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutl
methacrylate, n-hexyl methacrylate, isohexyl methacrylate, n-octyl
methacrylate, isooctyl methacrylate and 2-ethylhexyl methacrylate,
One of these (meth)acrylic esters alone or a combination of two or
more may be used.
[0074] The polar group-containing polypropylene-based resin (B2)
may also be obtained by copolymerizing a polar group-containing
copolymerizable monomer with both propylene and an .alpha.-olefin
other than propylene. Examples of this .alpha.-olefin include
ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene,
4-methyl-1-pentene and cyclohexene. This .alpha.-olefin may be
copolymerized with the polar group-containing copolymerizable
monomer by known methods, such as random copolymerization, block
copolymerization or graft copolymerization. From the standpoint of
affinity with the thermoplastic elastomer (A), the ratio of
structural units derived from the .alpha.-olefin other than
propylene as a percentage of the total structural units of the
polar group-containing polypropylene-based resin (B2) is in the
range of preferably 0 to 45 mol %, or more preferably 0 to 35 mol
%, or still more preferably 0 to 25 mol %.
[0075] The polar group of the polar group-containing
polypropylene-based resin (B2) may be subject to post-processing
alter polymerization. For example, they may be neutralized with a
metal ion of a (meth)acrylic acid group or a carboxyl group to
produce ionomers, or esterified with methanol, ethanol or the like.
Hydrolysis of vinyl acetate may be another option.
[0076] The melt flow rate (MFR) of the polar group-containing
polypropylene-based resin (B2) is in the range of preferably 0.1 to
300 g/10 min, or more preferably 0.1 to 100 g/min, or still more
preferably 1 to 15 g/10 min under conditions of 230.degree. C.,
load 2.16 kg (21.18 N). If the MFR of the polar group-containing
polypropylene-based resin (B2) under these conditions is at least
0.1 g/10 min, the thermoplastic polymer composition has excellent
forming processability, while if it is not more than 300 g/10 min
the thermoplastic polymer composition has excellent extensibility.
From the standpoint of heat resistance and adhesiveness, the
melting point of the polar group-containing polypropylene-based
resin (B2) is in the range of preferably 100.degree. C. to
180.degree. C. or more preferably 110.degree. C. to 170.degree. C.,
or still more preferably 120.degree. C. to 145.degree. C.
[0077] The ratio of the polar group-containing structural units as
a percentage of the total structural units of the polar
group-containing polypropylene-based resin (B2) is in the range of
preferably 0.01 to 10 mass %, or more preferably 0.01 to 5 mass %,
or still more to preferably 0.2 to 1 mass %. If the ratio of the
polar group-containing structural units is at least 0.01 mass %,
adhesiveness to the adherend is high, while if it is not more than
10 mass % affinity with the thermoplastic elastomer (A) is
improved, resulting in better extensibility and adhesiveness and
suppressing gel formation. To optimize the ratio of polar
group-containing structural units, a highly-concentrated polar
group-containing polypropylene-based resin with a high ratio of
polar group-containing structural units may be diluted with a
polypropylene-based resin containing no polar group-containing
structural units and used as the polar group-containing
polypropylene-based resin (B2).
[0078] From the standpoint of forming processability, extensibility
and adhesiveness, the thermoplastic polymer composition preferably
contains a polar group-containing polyolefinic copolymer (C) in
addition to the polar group-containing polypropylene-based resin
(B2).
[0079] The content of the polar group-containing polyolefin-based
copolymer (C) in the thermoplastic polymer composition is in the
range of preferably 5 to 100 mass parts, or more preferably 20 to
70 mass pans, or still more preferably 35 to 60 mass parts per 100
mass parts of the thermophilic elastomer (A). If the content of the
polar group-containing polyolefin-based copolymer (C) is at least 5
mass parts, adhesiveness tends to be good at temperatures of not
more than 190.degree. C., while if it is not more than 100 mass
parts, flexibility and extensibility tend to be good.
[0080] The polar group-containing polyolefin-based copolymer (C) is
preferably a polyolefin-based copolymer including an olefin-based
copolymerizable monomer and a polar group-containing
copolymerizable monomer. Examples of the olefin-based
copolymerizable monomer include ethylene, 1-butene, 1-pentene,
1-hexene, 1-octene, 4-methyl-1-pentene and cyclohexene. One of
these may be used alone, or two or more may be combined. Of these,
ethylene is preferred from the standpoint of adhesiveness.
[0081] Examples of the polar group of the polar group-containing
polyolefin-based copolymer (C) include an ester group hydroxyl
group, carboxyl group, acid anhydride group or amido group, or a
halogen atom such as a chlorine atom, and examples of the polar
group-containing copolymerizable monomer include (meth)acrylic
esters, (meth)acrylic acid, vinyl acetate, vinyl chloride, ethylene
oxide, propylene oxide and acrylamide. One of these polar
group-containing copolymerizable monomers may be used alone, or two
or more may be combined. Of these, a (meth)acrylic ester is
preferred from the standpoint of adhesiveness.
[0082] Examples of (meth)acrylic esters that are preferred as the
polar group-containing copolymerizable monomer include acrylic acid
alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl
acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate,
n-hexyl acrylate, isohexyl acrylate, n-octyl acrylate, isooctyl
acrylate and 2-ethylhexyl acrylate; and methacrylic acid alkyl
esters such as methyl methacrylate, ethyl methacrylate, n-propyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate,
isobutyl methacrylate, n-hexyl methacrylate, isohexyl methacrylate,
n-octyl methacrylate, isooctyl methacrylate and 2-ethylhexyl
methacrylate, and one of these alone or a combination or two or
more may be used. Of these, an acrylic acid alkyl ester is
preferred for obtaining strong adhesiveness even with heat
treatment at temperatures of 190.degree. C. or less, methyl
acrylate and ethyl acrylate are especially preferred, and methyl
acrylate is especially still more preferred.
[0083] The form of polymerization of the polar group-containing
polyolefin-based copolymer
[0084] (C) is not particularly limited. Moreover, the polar groups
of the polar group-containing polyolefinic copolymer (C) may also
be post-processed after polymerization.
[0085] The MFR of the polar group-containing olefin-based copolymer
(C) under conditions of 190.degree. C., load 2.16 kg (21.18 N) is
in the range of preferably 0.1 to 100 g/10 min, or more preferably
0.1 to 70 g/10 min, or still more preferably 1 to 30 g/10 min, or
yet more preferably 1 to 20 g/10 min. If the MFR of the polar
group-containing polyolefin-based copolymer (C1) is at least 0.1
g/10 min, adequate adhesiveness is obtained even with heat
treatment at 190.degree. C. or less, while if it is not more than
100 g/10 min manufacturing is easier, and excellent extensibility
and adhesiveness are obtained.
[0086] The Vicat softening point of the polar group-containing
polyolefin-based copolymer (C) is in the range of preferably
40.degree. C. to 100.degree. C., or more preferably 45.degree. C.
to 55.degree. C. If the Vicat softening point of the polar
group-containing polyolefin-based copolymer (C) is at least
40.degree. C., the thermoplastic polymer composition gains good
extensibility and adhesiveness, while if it is not more than
100.degree. C. excellent adhesiveness is obtained even with heat
treatment at 190.degree. C. or less.
[0087] The ratio of the polar group-containing structural units as
a percentage of the total structural units of the polar
group-containing polyolefin-based copolymer (C) is in the range of
preferably 1 to 99 mass %, or more preferably 1 to 50 mass %, or
still more preferably 5 to 30 mass %. If the ratio of the polar
group-containing structural units is within this range, good
affinity and compatibility are obtained not only with the
thermoplastic elastomer (A) but also with the adhesion imparting
component (B), giving the thermoplastic polymer composition good
extensibility and adhesiveness and increasing the adhesiveness on
the adherend. If the ratio of the polar group-containing structural
units is too low, the extensibility of the thermoplastic polymer
composition tends to be less, while if the ratio is too high,
affinity and compatibility with the thermoplastic elastomer (A)
tend to be lower.
[0088] The thermoplastic polymer composition may also contain a
tackifier resin (D). Forming processability can be further improved
while maintaining adhesiveness if a tackifier resin (D) is
included. The tackifier resin (D) may be an aliphatic unsaturated
hydrocarbon resin, aliphatic saturated hydrocarbon resin, alicyclic
unsaturated hydrocarbon resin, alicyclic saturated hydrocarbon
resin, aromatic hydrocarbon resin, hydrogenated aromatic
hydrocarbon resin, rosin ester resin, hydrogenated rosin ester
resin, terpene phenol resin, hydrogenated terpene phenol resin,
terpene resin, hydrogenated terpene resin, aromatic
hydrocarbon-modified terpene resin, coumarone-indene resin, phenol
resin or xylene resin for example, and one of these alone or a
combination of two or more may be used. Of these, an aliphatic
saturated hydrocarbon resin, alicyclic saturated hydrocarbon resin,
hydrogenated aromatic hydrocarbon resin or hydrogenated terpene
resin is preferred, and a hydrogenated aromatic hydrocarbon resin
or hydrogenated terpene resin is especially preferred.
[0089] The softening point of the tackifier resin (D) is in the
range of preferably 50.degree. C. to 200.degree. C., or more
preferably 65.degree. C. to 180.degree. C., or still more
preferably 80.degree. C. to 160.degree. C. If she softening point
is at least 50.degree. C. the multilayer film can maintain
adhesiveness at the temperatures at which the molded body of the
present invention is used, while if it is not more than 200.degree.
C. it can maintain adhesiveness at the heat processing temperature
during adhesion. The softening point here is a value measured in
accordance with ASTM28-67.
[0090] When the tackifier resin (D) is included in the
thermoplastic polymer composition, the content thereof is
preferably in the range of 1 to 100 mass parts, or more preferably
5 to 70 mass parts, or still more preferably 10 to 45 mass parts
per 100 mass parts of the thermoplastic elastomer (A) from the
standpoint of flexibility and extensibility.
[0091] The thermoplastic polymer composition may also contain a
softener (S). Examples of this softener (S) include softeners
commonly used in rubber and plastics, represented by parafin-based,
naphthene-based and aromatic-based process oils; phthalic acid
derivatives such as dioctyl phthalate and dibutyl phthalate; and
white oil, mineral oil, oligomers of ethylene and .alpha.-olefins,
paraffin wax, fluid paraffin, polybutene, low-molecular-weight
polybutadiene and low-molecular-weight polyisoprene. Of these a
process oil is preferred, and a paraffin-based process oil is
especially preferred. It is also possible to use known softeners
commonly used in combination with polyvinyl acetal resins,
including organic acid ester-based plasticizers such as monobasic
organic acid esters and polybasic organic acid esters, and
phosphate-based plasticizers such as organic phosphoric acid esters
and organic phosphorous acid esters.
[0092] Examples of basic organic acid esters include esters of
alcohols with polybasic organic acids such as adipic acid, sebacic
acid and azelaic acid; and glycol-based esters obtained by
reactions between glycols such as methylene glycol, tetraethylene
glycol and tripropylene glycol and monobasic organic acids such as
butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid,
heptylic acid, n-octylic acid, 2-ethylhexylic acid, pelargonic acid
(n-nonylic acid) and decylic acid, of which typical examples are
triethylene glycol-di-caproic acid ester, triethylene
glycol-di-2-ethylbutyric acid ester, triethylene
glycol-di-n-octylic acid ester and triethylene
glycol-di-2-ethylhexylic acid ester. Examples of polybasic organic
acid esters include sebacic acid dibutyl ester, azelaic acid
dioctyl ester and adipic acid dibutylcarbitol ester. Examples of
organic phosphoric acid esters include tributoxyethyl phosphate,
isodecylphenyl phosphate and triisopropyl phosphate. One kind of
the softening agent (S) alone or a combination of two or more kinds
may be used.
[0093] From the standpoint of forming processability and
adhesiveness, the content of the softening agent (S) in the
thermoplastic polymer composition is in the range of preferably 0.1
to 300 mass pasts or more preferably 1 to 200 mass parts, or still
more preferably 10 to 200 mass parts, or especially preferably 50
to 150 mass parts per 100 mass parts of the thermoplastic elastomer
(A).
[0094] The thermoplastic polymer composition may also contain
another thermoplastic polymer such as an olefin-based polymer,
styrene-based polymer, polphenylene ether-based resin or
polyethylene glycol. Examples of olefin-based polymers include
block copolymers and random copolymers of polyethylene,
polypropylene polybutene and propylene with other .alpha.-olefins
such as ethylene and 1-butene. When another thermoplastic polymer
is included, the content thereof is preferably not more than 100
mass parts, or more preferably not more than 50 mass parts, or
still more preferably not more than 2 mass parts per 100 mass parts
of the thermoplastic elastomer (A).
[0095] From the standpoint of heat resistance, weather resistance
and hardness adjustment the thermoplastic polymer composition may
also contain an inorganic filler. Examples of the inorganic filler
include calcium carbonate, talc, magnesium hydroxide, aluminum
hydroxide, mica, clay, natural silicic acid, synthetic silicic
acid, titanium oxide, carbon black, barium sulfate, glass
microspheres and glass fiber, and one of these alone or a
combination of two or more may be used. When an inorganic filler is
included, the content thereof is preferably within a range that
does not adversely affect the flexibility of the thermoplastic
polymer composition, or preferably not more than 10 mass parts, or
more preferably not more than 5 mass parts, or still more
preferably not more than 2 mass parts per 100 mass parts of the
thermoplastic elastomer (A).
[0096] The thermoplastic polymer composition may also contain an
antioxidant lubricant light stabilizer, processing aid, pigment,
dye or other coloring agent, flame retardant, antistatic agent,
matting agent, silicon oil, anti-blocking agent, UV absorber,
release agent, blowing agent, antibacterial agent, antifungal
agent, perfume or the like. Examples of antioxidants include
hindered phenol-based, phosphorus-based, lactone-based and
hydroxyl-based antioxidants. Of these, a hindered phenol-based
antioxidant is preferred. When an antioxidant is included, the
content thereof is preferably within a range that does not cause
discoloration when the resulting thermoplastic polymer composition
is melt kneaded, and is preferably in the range of 0.1 to 5 mass
parts per 100 mass parts of the thermoplastic elastomer (A).
[0097] The method lot preparing the thermoplastic polymer
composition is not particularly limited as long as it allows
uniform mixing of the included components, and an ordinary melt
kneading method may be used. Melt kneading may be accomplished with
a melt kneading apparatus such as a single-screw extruder,
twin-screw extruder, kneader, batch mixer, roller or Bunbury mixer,
and preferably the thermoplastic polymer composition is obtained by
melt kneading at a temperature in the range of 170.degree. C. to
270.degree. C.
[0098] The hardness of the thermoplastic polymer composition as
measured by the JIS-A method of JIS K 6253 is preferably not more
than 90, or more preferably in the range of 30 to 90, or still more
preferably in the range of 35 to 85. The flexibility and elastic
modulus tend to be lower if the hardness exceeds 90.
[0099] The MFR of the thermoplastic polymer composition is
preferable 1 to 50 g/10 min, or more preferably 1 to 40 g/10 min,
or still more preferably 2 to 30 g/10 min as measured under
conditions of 230.degree. C., load 2.16 kg (21.18 N) by methods
conforming to JIS K 7210. Within this range of MFR, forming
processabilities is good and the adhesive layer is easy to
prepare.
[0100] The thickness of the adhesive layer is in the range of
preferably 10 to 500 .mu.m, or more preferably 30 to 190 .mu.m, or
still more preferably 50 to 150 .mu.m. Adhesiveness declines if the
thickness of the adhesive layer is less than 10 .mu.m, while if it
exceeds 500 .mu.m, the handling properties, surface hardness and
excipiency tend to be poor.
[0101] The adhesive strength of the thermoplastic -polymer
composition is preferably at least 20 N/25 mm, or more preferably
at least 30 N/25 mm, or still more preferably at least 60 N/25 mm.
Adhesive strength here is a valise measured by the methods
described in the examples in accordance with JIS K 6854-2.
[0102] The amorphous resin constituting the base layer must have an
elastic modulus of 2 to 600 MPa at an arbitrary temperature of
110.degree. C. to 160.degree. C. If the elastic modulus is less
than 2 MPa, elongation during vacuum molding tends not to be
uniform, while if it exceeds 600 MPa, cracks and breakage tend to
occur during vacuum molding. The elastic modulus is expressed in
[MPa] units with the first decimal place rounded off. An "amorphous
resin" in this Description is a resin that does not exhibit a clear
melting point in a differential scanning calorimetry (DSC)
curve.
[0103] Examples of amorphous resins include polystyrene resin,
polyvinyl chloride resin, acrylonitrile styrene resin, acrylonitril
butadiene styrene resin, polycarbonate resin and methacrylic-based
resins. Of these, a methacrylic-based resin is preferred from the
standpoint of transparency, weather resistance, surface glossiness
and abrasion resistance, and a methacrylic-based resin containing
the methacrylic resin (F) and the elastic body (R) is more
preferred.
[0104] The methacrylic-based resin preferably contains 10 to 99
mass parts of the methacrylic resin (F) and 90 to 1 mass parts of
the elastic body (R), or more preferably 55 to 90 mass parts of the
methacrylic resin (F) and 45 to 10 mass parts of the elastic body
(R), or still more preferably 70 to 90 mass parts of the
methacrylic resin (F) and 30 to 10 mass parts of the elastic body
(R). If the content of the methacrylic resin (F) is less than 10
mass parts, the surface hardness of the resulting base layer tends
to decline.
[0105] A structural unit derived from methyl methacrylate
preferably constitutes at least 80 mass %, or more preferably at
least 90 mass % of the methacrylic-based resin (F). In other words,
structural units not derived from methyl methacrylate preferably
constitute not more than 20 mass %, or more preferably not more
than 10 mass % of the methacrylic-based resin (F), which may be a
polymer having methyl methacrylate as its sole monomer.
[0106] Such monomers other than methyl, methacrylate include
acrylic acid esters such as methyl acrylate, ethyl acrylate,
n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl
acrylate, s-butyl acrylate, tert-butyl acrylate, amyl acrylate,
isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate,
pentadecyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl
acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate,
2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate,
cyclohexyl acrylate, norbornenyl acrylate and isobonyl acrylate;
methacrylic acid esters other than methyl methacrylate, such as
ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate,
n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate,
tert-butyl methaery late, amyl methacrylate, isoamyl methacrylate,
n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl
methacrylate, dodecyl methacrylate, phenyl methacrylate, benzyl
methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl
methacrylate, 2-ethoxyethyl methacrylate, glycidyl methacrylate,
allyl methacrylate, cyclohexyl methacrylate, norbornenyl
methacrylate and isobonyl methacrylate; unsaturated carboxylic
acids such as acrylic acid, methacrylic acid, maleic anhydride,
maleic acid and itaconic acid; olefins such as ethylene, propylene,
1-butene, isobutylene and 1-octene; conjugated dienes such as
butadiene, isoprene and myrcene; aromatic vinyl compounds such as
styrene, .alpha.-methylstyrene, p-methylstyrene and
m-methylstyrene; and acrylamide, methacrylamide, acrylonitrile,
methacrylonitrile, vinyl acetate, vinyl pyridine, vinyl ketone,
vinyl chloride, vinylidene chloride and vinylidene fluoride.
[0107] The tacticity of the methacrylic resin (F) is not
particularly limited, and one having isotactic, heterotactic,
syndiotactic or other tacticity may be used for example.
[0108] The weight-average molecular weight Mw(F) of the methacrylic
resin (F) is in the range of preferably 30,000 to 180,000, or more
preferably 40,000 to 150,000, or still more preferably 50,000 to
130,000. If the Mw(F) is less than 30,000, the impact resistance
and toughness of the resulting base layer tend to be less, while if
it exceeds 18,000 the flowability of the methacrylic resin (F)
tends to decline, detracting from the forming processability.
[0109] There are no particular limitations on the method for
manufacturing the methacrylic resin (F), which may be obtained
either by polymerizing monomers (a monomer mixture) of which methyl
methacrylate constitutes at least 80 mass %, or by copolymerizing
this a monomer other than methyl methacrylate. A commercial product
may also be used as the methacrylic resin (F). Examples of such
commercial products include "Parapet H1000B" (MFR 22 g/10 min
(230.degree. C., 37.3 N)), "Parapet GF" (MFR 15 g/10 min
(230.degree. C., 37.3 N)), "Parapet EH" (MFR 1.3 g/10 min
(230.degree. C., 37.3 N)), "Parapet HRL" (MFR 2.0 g/10 mm
(230.degree. C., 37.3 N)), "Parapet HRS" (MFR 2.4 g/10 min
(230.degree. , 37.3 N)) and "Parapet G" (MFR 8.0 g/10 min
(230.degree. C., 37.3 N)) (all of these are name of products
manufactured by Kuraray Co., Ltd.).
[0110] Examples of the elastic body include butadiene-based rubber,
chloroprene-based rubber, block copolymers and multilayer
structures, and these may be used independently or combined. Of
these, a block copolymer or multilayer structure preferred from the
standpoint of transparency, impact resistance and dispersibility,
and the block copolymer (G) or multilayer structure (E) is
especially preferred.
[0111] The block copolymer (G) has a methacrylic ester polymer
block (g1) and an acrylic ester polymer block (g2). The block
copolymer (G) may have only one each of the methacrylic ester
polymer block (g1) and acrylic ester polymer block (g2), or may
have more than one of the same.
[0112] The principal constituent unit of the methacrylic ester
polymer block (g1) is a structural unit derived from a methacrylic
ester. The ratio of the structural unit derived from a methacrylic
ester in the methacrylic ester polymer block (g1) is preferably at
least 80 mass %, or more preferably at least 90 mass %, or still
more preferably at least 95 mass %, or especially preferably at
least 98 mass % from the standpoint of extensibility and surface
hardness.
[0113] Examples of the methacrylic ester include methyl
methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, isobutyl methacrylate,
sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate,
isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl
methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate,
dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate,
benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl
methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate
and allyl methacrylate, and one of these alone or a combination of
two or more may be polymerized. Of these, a methacrylic acid alkyl
ester such as methyl methacrylate, ethyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, tert-butyl methacrylate,
cyclohexyl methacrylate or isobornyl methacrylate is preferred from
the standpoint of transparency and heat resistance, and methyl
methacrylate is especially preferred.
[0114] The methacrylic ester polymer block (g1) may also contain a
structural unit derived from a monomer other than a methacrylic
ester, and from the standpoint of extensibility and surface
hardness, the ratio of this unit is preferably not more than 20
mass %, or more preferably not more than 10 mass %, or still more
preferably not more than 5 mass %, or especially preferably not
more than 2 mass %.
[0115] Examples of the monomer other than a methacrylic ester
include acrylic esters, unsaturated carboxylic acids, aromatic
vinyl compounds, olefins, conjugated dienes, acrylonitrile,
methacrylonitrile, acrylamide, methacrylamide, vinyl acetate, vinyl
pyridine, vinyl ketone, vinyl chloride, vinylidene chloride and
vinylidene fluoride, and one of these alone or a combination of two
or more may be used.
[0116] The weight-average molecular weight of the methacrylic ester
polymer block (g1) is in the range of preferably 5,000 to 150,000,
or more preferably 8,000 to 120,000, or still more preferably
12,000 to 100,000. If the weight-average molecular weight is less
that 5,000, elasticity declines, and wrinkles tend to occur during
stretch forming at high temperatures, while if it exceeds 150,000,
three-dimensional overlaying formability declines, and breakage is
more likely during stretch forming.
[0117] When the block copolymer (G) has a plurality of methacrylic
ester polymer block (g1), the compositional ratios and molecular
weights of the structural units making up the respective
methacrylic ester polymer blocks (g1) may be either the same or
different.
[0118] The total weight-average molecular weight Mw(g1-total) of
the methacrylic ester polymer blocks(s) (g1) per molecule of the
block copolymer (G) is preferably 20,000 to 150,000, or more
preferably 15,0000 to 120,000, or still more preferably 20,000 to
100,000. When the block copolymer (G) has only one methacrylic
ester polymer block (g1) per molecule, the weight-average molecular
weight of the methacrylic ester polymer block (g1) is the same as
the Mw(g1-total). When the block copolymer (G) has a plurality of
methacrylic ester polymer blocks (g1) per molecule, the
Mw(g1-total) is the sum of the weight-average molecular weights of
each of the methacrylic ester polymer blocks (g1).
[0119] When using a mixture of multiple block copolymers (G) having
methacrylic ester polymer blocks (g1) with different weight-average
molecular weights, the mixing ratio of each block copolymer (G) is
multiplied by the weight average molecular weight of the
methacrylic ester polymer block (g1) of each, and the sum is given
as the Mw(g1-total)
[0120] The ratio of fire weight-average molecular weight Mw(F) of
the methacrylic resin (F) to the Mw(g1-total), that is
Mw(F)/Mw(g1-total), is in fee range of preferably 0.3 to 4.0, or
more preferably 1.0 to 3.5, or still more preferably 1.5 to 3.0. If
Mw(F)/Mw(g1-total) is less than 0.3, the impact resistance and
surface smoothness of the resulting base layer tend to decline,
while if it exceeds 4.0 the surface smoothness of the base layer
and the haze temperature dependence tend to be worse.
[0121] From the standpoint of transparency, flexibility, forming
processability and surface smoothness, the ratio of the methacrylic
ester polymer block (g1) in the block copolymer (G) is in the range
of preferably 10 to 70 mass %, or more preferably 25 to 60 mass %.
When the block copolymer (G) has a plurality of methacrylic ester
polymer block (g1), this ratio is calculated based on the total
mass of all the methacrylic ester polymer blocks (g1).
[0122] The principal constituent unit of the acrylic ester polymer
block (g2) is a structural unit derived from an acrylic acid ester.
The ratio of the structural unit derived from an acrylic acid ester
in the acrylic ester polymer block (g2) is preferably at least 45
mass %, or more preferably at least 50 mass %, or still more
preferably at least 60 mass %, or especially preferably at least
mass % from the standpoint three-dimensional overlaying formability
and extensibility.
[0123] Examples of this acrylic acid ester include methyl acrylate,
ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl
acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl
acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate,
cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate,
dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl
acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate,
2-methoxyethyl acrylate, glycidyl acrylate and allyl acrylate, and
one of these may alone or a combination of two or more may be
polymerized.
[0124] From the standpoint of extensibility and transparency, the
acrylic ester polymer block (g2) preferably consists of an acrylic
acid alkyl ester and a (meth)acrylic acid aromatic ester. Examples
of the acrylic acid alkyl ester include methyl acrylate, ethyl aery
laic, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate
and dodecyl acrylate. Of these, n-butyl acrylate and 2-ethylhexyl
acrylate are preferred.
[0125] A (meth)acrylic acid aromatic ester means an acrylic acid
aromatic ester or methacrylic acid aromatic ester, and comprises a
compound containing an aromatic ring, ester bonded to (meth)acrylic
acid. Examples of this (meth)acrylic acid aromatic ester include
phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, styryl
acrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl
methacrylate and styryl methacrylate. Of these, phenyl
methacrylate, benzyl methacrylate, phenoxyethyl methacrylate and
benzyl acrylate are preferred from the standpoint of
transparency.
[0126] When the acrylic ester polymer block (g2) consists of a an
acrylic acid alkyl ester and a (meth)acrylic acid aromatic ester,
from the standpoint of transparency the acrylic ester polymer block
(g2) preferably comprises 50 to 90 mass % structural units derived
from the acrylic acid alkyl ester and 50 to 10 mass % structural
units derived from the (meth)acrylic acid aromatic ester or more
preferably 60 to 80 mass % structural units derived from the
acrylic acid alkyl ester and 40 to 20 mass % structural units
derived from the (meth)acrylic acid aromatic ester.
[0127] The acrylic ester polymer block (g2) may also contain a
structural unit derived from a monomer other than an acrylic ester,
and in this case the content thereof in the acrylic ester polymer
block (g2) is preferably not more than 55 mass %, or more
preferably not more than 50 mass %, or still more preferably not
more than 40 mass %, or especially preferably not more than 10 mass
%.
[0128] Examples of the monomer other than an acrylic ester include
methacrylic esters, unsaturated carboxylic acids, aromatic vinyl
compounds, olefins, conjugated dienes, acrylonitrile,
methacrylonitrile, acrylamide, methacrylamide, vinyl acetate, vinyl
pyridine, vinyl ketone, vinyl chloride, vinylidene chloride and
vinylidene fluoride, and one of these alone or a combination of two
or more may be used.
[0129] From the standpoint of three-dimensional overlaying
formability and extensibility, the weight-average molecular weight
of the acrylic ester polymer block (g2) is in the range of
preferably 5,000 to 120,000, or more preferably 15,000 to 110,000,
or still more preferably 30,000 to 100,000.
[0130] When the block copolymer (G) has a plurality of acrylic
ester polymer block (g2), the compositional ratios and molecular
weights of the structural units making up the respective acrylic
ester polymer blocks (g2) may be either the same or different.
[0131] The total weight-average molecular weight Mw(g2-total) of
the acrylic ester polymer block(s) (g2) per molecule of the block
copolymer is in the range of preferably 30,000 to 140,000, or more
preferably 40,000 to 110,000, or still more preferably 50,000 to
100,000. If the Mw(g2-total) is less than 50,000 the resulting base
layer tends to have poor impact resistance, while if it exceeds
140,000 the resulting base layer tends to have less surface
smoothness. When the block copolymer (G) has only one acrylic ester
polymer block (g2) per molecule, the weight-average molecular
weight of the acrylic ester polymer block (g2) is the same as the
Mw(g2-total). When the block copolymer (G) has a plurality of
acrylic ester polymer blocks (g2) per molecule, on the other hand,
the Mw(g2-total) is the total of the weight-average molecular
weights of each of the acrylic ester polymer blocks (g2).
[0132] When using a mixture of multiple block copolymers (G) having
methacrylic ester polymer blocks (g2) with different weight-average
molecular weights, the mixing ratio of each block copolymer (G) is
multiplied by the weight average molecular weight of the
methacrylic ester polymer block (g2) of each, and the sum is given
as the Mw(g2-total).
[0133] The weight-average molecular weight of the methacrylic ester
polymer block (g1) and the weight-average molecular weight of the
acrylic ester polymer block (g2) are values calculated from the
weight average molecular weight of the intermediate products and
the final product (block copolymer (G)) as measured from samples
taken during and after polymerization in the process of
manufacturing block copolymer (G). Each weight-average molecular
weight is a standard polystyrene equivalent value as measured by
GPC.
[0134] From the standpoint of transparency, flexibility, forming
processability and surface smoothness, the ratio of the acrylic
ester polymer block (g2) in the block copolymer (G) is in the range
of preferably 30 to 90 mass %, or more preferably 40 to 75 mass %.
When the block copolymer (G) has a plurality of acrylic ester
polymer block (g2), this ratio is calculated based on the total
mass of all the acrylic ester polymer blocks (g2).
[0135] The form of binding of the methacrylic ester polymer block
(g1) and acrylic ester polymer block (g2) in the block copolymer
(G) is not particularly limited, and for example the methacrylic
ester polymer block (g1) and acrylic ester polymer block (g2) may
be connected serially, with one end of the acrylic ester polymer
block (g2) connected to one end of the methacrylic ester polymer
block (g1) ((g1)-(g2) structure); or with one end of the acrylic
ester polymer block (g2) connected to both ends of the methacrylic
ester polymer block (g1) ((g2)-(g1)-(g2) structure); or with one
end of the methacrylic ester polymer block (g1) connected to both
ends of the acrylic ester polymer block (b2) ((g1)-(g2)-(g1)
structure). Other possibilities include star block copolymers, such
as radial structures including multiple block copolymers with
(g1-(g2) structures attached at one end ([(g1)-(g2)-]nX and
([(g2)-(g1)-]nX structures), and radial structure including
multiple block copolymers with (g1)-(g2)-(g1) structures attached
at one end ([(g1)-(g2)-(g2)-]nX structure) or multiple block
copolymers with (g2)-(g1)-(g2) structures attached at one end
([(g2)-(g1)-(g2)-]nX structure), as well as block copolymers with
branched structures. X here represents a coupling agent residue. Of
these, diblock copolymers, triblock copolymers and star block
copolymers are preferred from the standpoint of surface smoothness
and impact resistance (g1)-(g2) diblock copolymers, (g1)-(g2)-(g1)
triblock copolymers, [(g1)-(g2)-]nX star block copolymers and
([(g1)-(g2)-(g2)-]nX star block copolymer are especially preferred,
and (g1)-(g2)-(g1) triblock copolymers are especially still more
preferred.
[0136] The block copolymer (G) may also have another polymer block
(g3) other than the methacrylic ester polymer block (g1) and
acrylic ester polymer block (g2). The principal structural unit
constituting the polymer block (g3) is a structural unit derived
from a monomer that is not a methacrylic ester or acrylic ester,
and examples of this monomer include olefins such as ethylene,
propylene, 1-butene, isobutylene and 1-octene; conjugated dienes
such as butadiene, isoprene and myrcene, aromatic vinyl compounds
such as styrene, .alpha.-methylstyrene, p-methystyrene and
m-methylstyrene; and vinyl acetate, vinyl pyridine, acrylonitrile,
methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene
chloride, vinylidene fluoride, acrylamide, methacrylamide,
.epsilon.-caprolactone and valerolactone.
[0137] When the block copolymer (G) has the polymer block (g3), the
form of binding of the methacrylic ester polymer block (g1),
acrylic ester polymer block (g2) and polymer block (g3) is not
particularly limited, and may be for example a (g1)-(g2)-(g1)-(g3)
or (g3)-(g1)-(g2)-(g1)-(g3) block copolymer structure. When the
block copolymer (G) has a plurality of polymer block (g3), the
compositional ratios and molecular weights of the structural units
making up the respective polymer blocks (g3) may be either the same
or different.
[0138] The block copolymer (G) may also have a functional group
such as a hydroxyl group, carboxyl group, acid anhydride, amino
group either in the molecular chain or at the end of the molecular
chain.
[0139] The weight-average molecular weight Mw(G) of the block
copolymer (G) is in the range of preferably 60,000 to 400,000, or
more preferably 100,000 to 200,000, if the weight-average molecular
weight of the block copolymer (G) is less than 60,000, a good flat
molded body is difficult to obtain, because adequate melt tension
cannot be maintained during melt extrusion molding, and the
breaking strength and other mechanical properties of the resulting
flat molded body tend to be less, while if it exceeds 400,000 the
viscosity of the molten resin increases, and fine textural
irregularities and seeding caused by unmelted material
(high-molecular-weight material) tend to occur on the surface of a
flat molded body obtained by melt extrusion molding, making a good
flat molded body difficult to obtain.
[0140] The molecular weight distribution of the block copolymer (G)
is in the range of preferably 1.0 to 2.0, or more preferably 1.0 to
1.6. If the molecular weight distribution is within this range, the
content of unmelted material that causes seeding in the base layer
can be reduced. The weight-average molecular weight and
number-average molecular weight are the standard polystyrene
equivalent weights as measured by GPC.
[0141] The refractive index of the block copolymer (G) is in the
range of preferably 1.485 to 1.495, or more preferably 1.487 to
1.493. If the refractive index is within this range, the resulting
base layer is highly transparent. The refractive index is a value
measured at a wavelength of 587.6 nm (d line).
[0142] The method for manufacturing the block copolymer (G) is not
particularly limited, and may be consistent with known techniques
and for example methods involving living polymerization of the
monomers constituting the individual polymer blocks are commonly
used. Such living polymerization techniques include for example a
method of anionic polymerization in the presence of an alkali metal
or a mineral acid salt such as an alkali earth metal salt, using an
organic alkali metal compound as a polymerization initiator; a
method of anionic polymerization in the presence of an organic
aluminum compound, using an organic alkali metal compound as a
polymerization initiator; a method of polymerization using an
organic rare earth metal complex as a polymerization initiator; and
a method of radical polymerization in presence of a copper compound
using an .alpha.-halogenated ester compound as an initiator.
Another method is to manufacture a mixture containing the block
copolymer (G) by polymerizing the monomers constituting the various
blocks using a polyvalent radical polymerization initiator or
polyvalent radical chain transfer agent. Of these methods, the
method of anionic polymerization in the presence of an organic
aluminum compound using an organic alkali metal compound as a
polymerization initiator is preferred because it yields a highly
pure block copolymer (G), allows easy control of the molecular
weight and compositional ratio, and is also economical.
[0143] The multilayer structure (E) contains at least 2 layers, an
inner layer (e2) and an outer layer (e1), and has at least one
layered structure in which the inner layer (e2) and outer layer
(e1) are disposed in this order from the middle layer in the
direction of the outermost layer. The multilayer structure (e) may
also have a crosslinkable resin layer (e3) on the inside of the
inner layer (e2) or the outside of the outer layer (e1).
[0144] The inner layer (e2) is a layer composed of a crosslinked
elastic body obtained by copolymerizing a monomer mixture having an
acrylic acid alkyl ester and a crosslinkable monomer.
[0145] An acrylic acid alkyl ester with 2 to 8 carbon atoms in the
alkyl group is preferred as the acrylic acid alkyl ester, and
examples include butyl acrylate and 2-ethylhexyl acrylate. From the
standpoint of impact resistance, the ratio of the acrylic acid
alkyl ester as a percentage of the total monomer mixture used to
form the copolymer of the inner layer (e2) is in the range of
preferably 70 to 99.8 mass %, or more preferably 80 to 90 mass
%.
[0146] The crosslinkable monomer used in the inner layer (e2) may
be any having at least two polymerizable carbon-carbon double bonds
per molecule, and examples include unsaturated carboxylic acid
diesters of glycols such as ethylene glycol dimethacrylate and
butanediol dimethacrylate, alkenyl esters of unsaturated carboxylic
acids, such as allyl acrylate, allyl methacrylate and allyl
cinnamate, polyalkenyl esters of polybasic acids, such as dially
phthalate, diallyl maleate, triallyl cyanurate and triallyl
isocyanurate, unsaturated carboxylic acid esters of polyhydric
alcohols, such as trimethylol propane triacrylate, and divinyl
benzene. An alkenyl ester of an unsaturated carboxylic acid or a
polyalkenyl ester of a polybasic acid is preferred. In order to
improve the impact resistance, heat resistance and surface hardness
of the base layer, the amount of the crosslinkable monomer as a
percentage of the total monomer mixture is in the range of
preferably 0.2 to 30 mass %, or more preferably 0.2 to 10 mass
%.
[0147] The monomer mixture forming the inner layer (e2) may also
comprise another monofunctional monomer. Examples of this
monofunctional monomer include alkyl methacrylates such as methyl
methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl
methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl
methacrylate, cyclohexyl methacrylate, dodecyl methacrylate,
myristyl methacrylate, palmityl methacrylate, stearyl methacrylate
and behenyl methacrylate, methacrylate acid esters, including
esters of methacrylic acid and phenols such as phenyl methacrylate
and esters of methacrylic acid and aromatic alcohols such as benzyl
methacrylate; aromatic vinyl-based monomers such as styrene,
.alpha.-methylstyrene, 1-vinyl naphthalene, 3-methylstyrene,
4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene,
2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene and halogenated
styrenes; vinyl cyanide-based monomers such as acrylonitrile and
methacrylonitrile; and conjugated diene-based monomers such as
butadiene and isoprene. To improve the impact resistance of the
base layer, the amount of the other monofunctional monomer as a
percentage of the total monomer mixture is preferably not more than
24.5 mass %, or more preferably not more than 20 mass %.
[0148] Considering the impact resistance of the base layer, the
outer layer (e1) is composed of a hard thermoplastic resin obtained
by polymerizing a monomer mixture containing at least 80% or
preferably at least 90 mass % methyl methacrylate. The hard
thermoplastic resin may also contain not more than 20 mass %, or
preferably not more than 10 mass % of another monofunctional
monomer.
[0149] Examples of the other monofunctional monomer include acrylic
acid alkyl esters such as methyl acrylate, butyl acrylate and
2-ethylhexyl acrylate; acrylic acid; and methacrylic acid.
[0150] Regarding the content ratio of the inner layer (e2) and
outer laser (e1) in the multilayer structure (E), the content ratio
of the inner layer (e2) is preferably selected from the range of 40
to 80 mass % and the content ratio of the outer layer (e1) is
preferably selected from the range of 20 to 60 mass % based on the
mass of the multilayer structure (E) (for example, the total of the
inner layer (e2) and outer layer (e1) when this consists of two
layers) considering the impact resistance, heat resistance, surface
hardness and handling properties of the base layer and the ease of
melt kneading with the methacrylic resin (F) and the like.
[0151] The method for manufacturing the multilayer structure (E) is
not particularly limited, but preferably it is manufactured by
emulsion polymerization in order to control the layer structure of
the multilayer structure (E).
[0152] The amorphous resin may also contain various additives such
as an antioxidant, heat stabilizer, lubricant, processing aid,
antistatic a gent, antioxidant, colorant or impact, resistance
aid.
[0153] The antioxidant by itself has the effect of preventing
oxidative deterioration of the resin in the presence of oxygen, and
examples include phosphorus-based antioxidants, hindered
phenol-based antioxidants and thioether-based antioxidants. One of
these antioxidants alone or a mixture of two or more may be used.
To reduce the loss of optical characteristics due to discoloration,
a phosphorus antioxidant or hindered phenol antioxidant is
preferred, and a combination of a phosphorus antioxidant and a
hindered phenol antioxidant is more preferred When a
phosphorus-based antioxidant and a hindered phenol-based
antioxidant are used together, the ratio thereof is not
particularly limited, but preferably the ratio of phosphorus-based
antioxidant hindered phenol-based antioxidant is in the range of
1/5 to 2/1 or more preferably 1/2 to 1/1.
[0154] Examples of phosphorus-based antioxidants include 2,2-
methylenebis(4,6-di-tert-butylphenyl)octyl phosphate (Asahi Denka
Co., Ltd.; ADK STAB HB-10), and tris(2,4-di-tert-butylphenyl)
phosphate (Ciba Specialty Chemicals, Inc.; Irugafos 168).
[0155] Examples of hindered, phenol-based antioxidants include
pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)
propionate] (Ciba Specialty Chemicals, Inc.; Irganox 1010).
octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Ciba
Specialty Chemicals, Inc.; Irganox 1076), and
3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphopha-
spyro [5.5]undecane (Adeka Corporation; ADK STAB PEP-36).
[0156] An anti-thermal degradation agent is a compound that can
reduce thermal degradation of the resin by capturing polymer
radicals produced when the amorphous resin reaches high
temperatures in an effectively oxygen-free condition, and examples
include
2-tert-butyl-6-(3'-tert-butyl-5'-methyl-hydroxybenzyl)-4-methylphenyl
acrylate (Sumitomo Chemical Co., Ltd.; Sumilizer GM), and
2,4-di-tert-amyl-6-(3',5'-di-tert-amyl-2'-hydroxy-.alpha.-methylbenzyl)ph-
enyl acrylate (Sumitomo Chemical Co., Ltd.; Sumilizer GS).
[0157] A UV absorber is a compound having the ability to absorb UV
rays, and examples include benxophenones, benzotriazoles,
triazines, benzoates, salicylates, cyanoacrylates, oxalic acid
anilides, malonic acid esters and formamidines. One of these alone
or a combination of two or more may be used. Of these,
benzotriazoles or anilides is preferred for controlling
bleed-out.
[0158] Example of benzotriazoles include
2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-yl)phe-
nol] (Asahi Denka Co., Ltd.; ADK STAB LA-31),
2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (Ciba
Specialty Chemicals, Inc.; Tinuvin 329), and
2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol
(Ciba Specialty Chemicals, Inc.; Tinuvin 234). Examples of anilides
include 2-ethyl-2'-ethoxy-oxalanilide (Clariant Japan K. K.;
Sanduvor VSU). Of these, benzotriazoles is preferred because it has
a strong suppression effect on resin deterioration caused by UV
rays.
[0159] A light stabilizer is compound that is primarily believed to
have the function of capturing radicals generated by oxidation
caused by light, and examples include hindered amines, such as
compounds having a 2,2,6,-tetralkylpiperidine framework.
[0160] A polymer processing aid is a compound that is effective for
improving the thickness accuracy and forming a thin film when
molding the amorphous resin, and is normally a polymer particle
with a particle diameter of 0.05 to 0.5 .mu.m manufactured by
emulsion polymerization This polymer particle may be a single-layer
particle consisting of a polymer with a single compositional ratio
and a single intrinsic viscosity, or it may be a multilayer
particle consisting of two or more polymers with different
compositional ratios and intrinsic viscosities. Of these, a
particle with a 2-layer structure including a polymer layer with a
low intrinsic viscosity as the inner layer and a polymer layer with
an intrinsic viscosity of at least 5 dl/g as the outer layer is
preferred. The polymer processing aid preferably has an intrinsic
viscosity in the range of 3 to 6 dl/g. If the intrinsic viscosity
is less than 3 dl/g the improvement effect on formability is less
while if it exceeds 6 dl/g the melt flowability of the amorphous
resin tends to be low.
[0161] The amorphous resin may also be used in a mixture with
another polymer. Examples of this other polymer include polyolefin
resins such as polyethylene, polypropylene (PP), polybutene-1,
poly-4-methylpentene-1 and polynorbornene; ethyle-based ionomers;
styrene-based resins such as polystyrene, styrene-maleic anhydride
copolymer, high impact polystyrene acrylonitrile-styrene copolymer,
acrylonitrile-butadiene-styrene copolymer (ABS),
acrylonitrile-ethylene-styrene copolymer, acrylonitrile-acrylic
ester-styrene copolymer, acrylonitrile-chlorinated
polyethylene-styrene copolymer and methyl
methacrylate-butadiene-styrene copolymer; methyl
methacrylate-styrene copolymer polyester resins such as
polyethylene terephthalate (PET) and polybutylene terephthalate;
polyamides such as nylon 6, nylon 66 and polyamide elastomer,
polycarbonate polyvinyl chloride, polyvinylidene chloride,
polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal,
vinyldene polyfluoride, polyurethane, modified polyphenylene ether,
polyphenylene sulfide and silicone modified resin; acrylic rubber
and silicone rubber; styrene-based thermoplastic elastomers such as
styrene-ethylene propylene-styrene copolymer
styrene-ethylene/butadiene-styrene copolymer and styrene-isoprene,
styrene copolymer, and olefin-based rubbers such as isoprene
rubber, ethylene propylene rubber and ethylene propylene diene
rubber.
[0162] The method for preparing the amorphous resin is not
particularly limited, but a method melt kneading and mixing is
preferred in order to increase the dispersibility of the various
components making up the amorphous resin. For example, a known
mixing or kneading apparatus such as a kneader rudder, extruder,
mixing roll or Bunbury mixer may be used for the mixing operation,
and a twin-screw extruder is preferred for improving kneadability
and compatibility. The temperature during mixing and kneading can
be adjusted appropriately according to the melting temperature of
the amorphous resin and the like, and is normally in the range of
110.degree. C. to 300.degree. C. When a twin-screw extruder is
used, the melt kneading is preferably performed using a vent at
reduced pressure and/or in a nitrogen atmosphere in order to
suppress discoloration. It is thus possible to obtain an amorphous
resin in any form, such as pellet or powder form. An amorphous
resin in pellet or powder form is suitable as a molding
material.
[0163] The base layer may be manufactured by a known method such as
the T-die method, inflation method, melt casting method or calendar
method. To obtain a base layer with good surface smoothness and low
haze, the method preferably includes a step in which the melt
kneaded product, is extruded from a T-die in a molten state and
then molded through contact with mirror roll surfaces or mirror
belt surfaces on both sides, or more preferably a step of molding
by pinching under pressure between mirror roll surfaces or mirror
belt, surfaces on both sides. The rolls or belts used here are
preferably all made of metal. The pinching pressure of the mirror
rolls or mirror belts is preferably a linear pressure of at least
10 N/mm, or more preferably at least 30 N/mm from the standpoint of
surface smoothness.
[0164] When the base layer is manufactured by the T-die method, for
example an extruder-type melt extrusion apparatus having a single
or twin extrusion screw may be used. The molding temperature for
manufacturing the base layer is in the range of preferably
200.degree. C. to 300.degree. C., or more preferably 220.degree. C.
to 270.degree. C. from the standpoint of forming processability and
product quality. When using a melt extrusion apparatus, it is
desirable to perform melt extrusion under reduced pressure or in a
nitrogen atmosphere using a vent in order to suppress
discoloration.
[0165] In the step of molding the amorphous resin in a molten state
by pinching it under pressure between mirror roll surfaces or
mirror belt surface on both sides, the surface temperature of at
least one of the mirror rolls or mirror belts on either side of the
amorphous resin is preferably at least 60.degree. C., and the
surface temperatures on both sides are preferably not more than
130.degree. C. If the surface temperatures of both mirror rolls or
mirror belts on either side of the amorphous resin are less than
60.degree. C., the base layer tends to have less surface smoothness
and haze, while if the surface temperature of at least one side
exceeds 130.degree. C., the surface smoothness of the resulting
base layer tends to be less or the haze tends to be greater.
[0166] The base layer may also be colored. The coloring method is
not particularly limited, and may be a method of including a
pigment or dye in the amorphous resin itself, or a method of
immersing the base layer in a liquid containing a dispersed
dye.
[0167] The roughness of the base layer is preferably not more than
1.5 nm, or more preferably in the range of 0.1 to 1.0 nm. Within
this range, the multilayer film of the present invention has
excellent surface smoothness, surface gloss and printing clarity.
It also has excellent light transmittance and other optical
characteristics for optical applications and excellent shaping
accuracy for surface shaping.
[0168] At a thickness of 75 .mu.m, the haze of the surface layer is
preferably not more than 0.3%, or more preferably not more than
0.2%. This is desirable because it provides for excellent printing
clarity in applications requiring design features, and also serves
to increase the utilization efficiency of the light source, in the
case of optical applications such as light guide films and
protective films for liquid crystal displays.
[0169] The thickness of the base layer is preferably in the range
of 10 to 500 .mu.m, or more preferably 40 to 300 .mu.m, or still
more preferably 50 to 200 .mu.m. If the base layer is less than 10
.mu.m thick the multilayer film is less strong and more likely to
warp during stretch forming and adhesion, while above a thickness
of 500 .mu.m the laminating properties, handling properties,
cutting properties, punching workability and the like are weakened,
and this makes the film unsuitable as the film becomes more
difficult to use as a film and more likely to break during vacuum
molding.
[0170] The base layer may be one that has undergone a stretching
process. The stretching process can increase the mechanical
strength and produce a base layer that is resistant to cracking.
The stretching method is not particularly limited, and may be
simultaneous biaxial stretching, sequential biaxial stretching,
tubular stretching or rolling for example. In order to achieve
uniform stretching and obtain a strong base layer, the temperature
during stretching is preferably (Tg+10).degree. C. to
(Tg+40).degree. C., given the glass transition temperature (Tg) of
the amorphous resin. If the stretching temperature is less than
(Tg+10).degree. C. the molded body is likely to break during
stretching, while if it exceeds (Tg+40).degree. C. the effects of
the stretching process may not be sufficient and the base layer may
be more unlikely strengthened. The stretching speed is normally
100% to 5,000% per minute. If the stretching speed is slow the
strength may not be sufficiently improved, and productivity also
declines. If the stretching speed is too fast the base layer may
break, and uniform stretching becomes difficult. Thermal setting is
preferably performed after stretching. A base layer with little
heat shrinkage can be obtained through thermal setting. The
thickness of the base layer obtained by stretching is preferably in
the range of 10 to 500 .mu.m. The glass transition temperature (Tg)
of the amorphous resin is determined by differential scanning
calorimetry (DSC).
[0171] The multilayer film of the present invention comprises a
base layer and an adhesive layer. The method of laminating the
adhesive layer may be a method of coating the base layer with a
solution of a thermoplastic polymer composition; a method of
laminating a film made of the thermoplastic polymer composition
onto the base layer; or a method of co-extruding the amorphous
resin and the thermoplastic polymer composition from a T-die. The
film made of the thermoplastic resin composition is obtained in the
same way as the base layer. From the standpoint of economy and
productivity, a co-extrusion molding method using a multi-manifold
die is particularly desirable.
[0172] In the multilayer film of the present invention, the
elongation at break of the amorphous resin as measured at a
temperature 5.degree. C. lower than the glass transition
temperature (Tg) is at least 160%, or preferably at least 200%, or
more preferably at least 25%. If the elongation at break is less
than 160% the multilayer film cannot be accurately shaped, and the
three-dimensional overlaying formability tends to be less,
resulting in breakage and wrinkles.
[0173] The base layer and or adhesive layer of the multilayer film
of the present invention may also be printed with pictures, words
graphics or other patterns or colors. The patterns may be either
colored or uncolored. Methods of printing include known printing
methods such as gravure printing, offset printing, screening
printing, transfer printing and inkjet printing. The printing
process preferably uses a resin composition commonly used in such
printing methods that contains a pigment or dye as a colorant and a
resin such as a polyvinyl resin, polyester resin, acrylic-based
resin, polyvinyl acetal resin or cellulose resin as a binder.
[0174] A metal or metal oxide may also be deposited on the base
layer in the multilayer film of the present invention. A metal or
metal oxide used in sputtering, vacuum deposition or the like may
be used as this metal or metal oxide, without any particular
limitations, and examples include gold, silver, copper, aluminum,
zinc, nickel, chromium, indium and oxides of these. These metals or
metal oxides may be used alone, or a mixture of two or more may be
used. Methods of depositing the metal or metal oxide on the base
laser include vacuum film-forming methods such as vapor deposition
and sputtering, and electroplating, electroless plating and the
like.
[0175] base layer side of the multilayer film preferably has a
pencil hardness of HB hardness or higher, and more preferably H
hardness or higher. If the pencil hardness is higher than HB the
multilayer film is hard to scratch, making it suitable as a
protective film.
[0176] The thickness of the multilayer film is in the range of
preferably 20 to 1,000 .mu.m, or more preferably 50 to 500 .mu.m,
or still more preferably 100 to 250 .mu.m. If the thickness of the
multilayer film is at least 20 .mu.m the multilayer film is easy to
manufacture, has excellent impact resistance and warpage reduction
during heating, and also has shielding properties during
coloration. If the film thickness is not more than 1,000 .mu.m, the
three-dimensional overlaying formability tends to be good.
[0177] The ratio of the thickness of the base layer to the
thickness of the adhesive layer is in the range of preferably 0.2
to 5, or more preferably 0.5 to 4, or still more preferably 0.8 to
3. If the ratio of the thickness of the base layer to the thickness
of the adhesive layer is less than 0.2 the surface hardness tends
to be low, and if it exceeds 5 the multilayer film tends to break
more easily, while if it exceeds 4 the stretchability tends to be
lower, and if it exceeds 3 the stretchability tends to be still
lower.
[0178] The molded body of the present invention comprises the
multilayer film of the present invention on the surface of an
adherend, and has excellent surface smoothness, surface hardness
and surface gloss. The adherend may be another thermoplastic resin,
a thermosetting resin, a wooden material or a non-wood fiber
substrate for example.
[0179] Example of other thermoplastic resins used as adherends
include polycarbonate resin, PET resin, polyamide resin,
polyethylene resin, polypropylene resin, polystyrene resin,
polyvinyl chloride resin (meth)acrylic resin and ABS resin.
Examples of thermosetting resins include epoxy resin, phenol resin
and melamine resin. Examples of non-wood fiber substrates include
kenaf substrates.
[0180] The method for manufacturing the molded body is not
particularly limited, and may be an insert forming method, vacuum
forming method, air-pressure forming method, compression forming
method, three-dimension overlay method (TOM forming) or the like,
but a vacuum forming method or TOM forming is preferred to allow
accurate forming and adhesion on a variety of adherends, and TOM
forming is especially preferred.
[0181] A method of manufacturing a molded body by TOM forming is
given as an example of a preferred embodiment. For example, the
vacuum forming apparatus described in Japanese Unexamined Patent
Application Publication No. 2002-067137 or the coating apparatus
described in Japanese Unexamined Patent Application Publication No,
2005-262502 may be used as the vacuum farming apparatus for TOM
forming the multilayer film, and this vacuum forming apparatus or
coating apparatus is equipped with a chamber box that can be sealed
and depressurized with the multilayer film and adherend inside.
[0182] The method for manufacturing the molded body by TOM forming
comprises a step of enclosing the multilayer film and adherend in
the chamber box; a step of reducing the pressure inside the chamber
box; a step of bisecting the interior of the chamber box with the
multilayer film; and a step of increasing the pressure in the
chamber box not having the adherend higher than the pressure in the
chamber box having the adherend, to thereby overlay the adherend
with the multilayer film. The step of bisecting the interior of the
chamber box with the multilayer film may be performed
simultaneously with the step of enclosing the multilayer film and
adherend in the chamber box.
[0183] In the step of reducing the pressure inside the chamber box,
the pressure inside the chamber box is preferably in the range of
0.1 to 20 kPa, or more preferably 0.1 to 10 kPa. If the pressure is
higher than 20 kPa it becomes difficult to accurately form the
multilayer film in the step of overlaying the adherend with the
multilayer film, while if it is less than 0.1 kPa productivity
tends to decrease because the forming process takes more time.
[0184] The method for manufacturing the molded body by TOM forming
preferably comprises a step of heating and softening the multilayer
film. In this step, the multilayer film is preferably heated to a
temperature range of 110.degree. C. to 160.degree. C., or more
preferably 110.degree. C. 140.degree. C. If the temperature of the
multilayer film is less than 110.degree. C., the multilayer film
does not soften properly, resulting in forming defects, and the
adhesive force of the multilayer film in the molded body tends to
be less. If it exceeds 160.degree. C., on the other hand,
over-softening and deterioration of the multilayer film may occur,
detracting from the quality of the molded body. The step of
reducing the pressure inside the chamber box and the step of
heating and softening the multilayer film may be performed
simultaneously.
[0185] In the step of increasing the pressure in the chamber box
not having the adherend higher than the pressure in the chamber box
having the adherend, the pressure in the chamber box not having the
adherend is preferably in the range of 50 to 500 kPa, or more
preferably 100 to 400 kPa. If the pressure in the chamber box not
having the adherend is less than 50 kPa, it becomes difficult to
accurately form the multilayer film in the step of overlaying the
adherend with the multilayer film. If the pressure in the chamber
box not having the adherend exceeds 500 kPa, productivity tends to
decline because it takes time to restore atmospheric pressure
(about 100 kPa) when removing the molded body from the chamber
box.
[0186] The method for increasing the pressure in the chamber box
not having the adherend higher than the pressure in the chamber box
having the adherend may be for example a method of exposing the
chamber box not having the adherend to atmospheric pressure, or
supplying pressurized air to the side of the chamber box not having
the adherend. By supplying pressurized air, it is possible to more
tightly mold the multilayer film on the adherend, and transfer the
shape of the adherend more accurately to the multilayer film.
[0187] The good three-dimensional overlaying formability, surface
hardness, extensibility, forming processability, adhesiveness and
shielding properties of the multilayer film of the present
invention make it suited to articles that require design features.
Examples include sign components such as billboards, signboards,
protecting signs, transom signs and rooftop signs; display
components such as show cases, partitions and shop displays;
lighting components such as fluorescent light covers, mood lighting
covers, lampshades, lighted ceilings, lighted walls and
chandeliers; interior components such as furniture, pendants and
mirrors; construction components such as doors, domes, safety
window glass, room partitions, staircase panels, balcony panels and
roofs of leisure structures; automobile exterior materials and
other transport-related components, such as automobile interior and
exterior parts and bumpers; electronic device components such as
audiovisual nameplates, stereo covers, vending machines, portable
phones and personal computers; incubators, rulers, communication
boards, greenhouses, water tanks, aquariums, bathroom materials,
clock panels, bathtubs, sanitary materials, desk mats, game
equipment, toys, musical instruments and wallpaper; and other
decorative applications such as masking films and various household
electronics. In this way, the multilayer film of the present
invention can be suitably used.
Examples
[0188] The present invention is explained in more detail below
using examples, but the present invention is not limited to these
examples. The physical properties in the examples and comparative
examples were evaluated by the following methods.
[Elastic Modulus]
[0189] Pellets of the amorphous resin were press molded into a film
(length 30 mm.times.width 5 mm.times.thickness 45 .mu.m), and the
storage elastic modulus was measured at a temperature of
110.degree. C. to 160.degree. C. and a frequency of 1 Hz in
temperature dependency mode with a kinetic viscosity measurement
device (Rheology Co., Ltd.; DVE-V4FT Rheospectra).
[Elongation at Break]
[0190] A value for elongation at break of the multilayer film was
obtained by the method conforming to JIS K 7161 at a temperature
5.degree. C. lower than the glass transition temperature (Tg) of
the amorphous resin, using a tensile tester (Instron; 5566
Universal Testing Machine).
[Surface Hardness]
[0191] The surface hardness on the base layer side of the
multilayer film was measured under conditions of pitch 2 mm, load
10 N in accordance with JIS K 5600-5-4 using a pencil hardness
tester (Toyo Setki Seisaku-sho, Ltd.; manual pencil hardness
tester).
[Shielding]
[0192] The multilayer film was held up to a fluorescent light, and
light permeability was evaluated visually.
[0193] A+: Almost no light permeation
[0194] A: Little light permeation
[0195] B: Complete light permeation
[Three-Dimensional Overlaying Formability]
[0196] A multilayer film (length 210 mm.times.width 297 mm) and a
concave metal mold (length 250 mm.times.width 160 mm.times.depth 25
mm) were inserted into a vacuum pressure forming machine (Fu-se
Vacuum Forming Ltd.; NGF 0406 forming machine) with the adhesive
layer facing the mold, the multilayer film was heated to
110.degree. C., a three-dimensional overlay method (TOM forming)
similar to the method described below with respect to Example 1 was
implemented to form the elongated multilayer film into a box shape,
and the formability of the multilayer film was evaluated visually.
The forming temperature was also raised to 160.degree. C. in
10.degree. C. increments, and multilayer films were formed and
formability evaluated by the same methods.
[0197] A: Accurate forming with no breakage of the multilayer films
formed at any of the temperatures from 110.degree. C. to
160.degree. C.
[0198] B: Breaking or wrinkling of some of the multilayer films
formed at temperatures from 110.degree. C. to 160.degree. C.
[Adhesive Strength]
[0199] The multilayer film was heated to 130.degree. C., the base
layer side of a molded body prepared by the method described below
was fixed with strong adhesive tape (Nitto Denko Corporation;
Hyperjoint H9004) to a stainless steel (SUS) plate, and the peeling
strength between the base layer and the adherend was measured under
conditions of peeling angle 180.degree., tension rate 300 mm/min,
environmental temperature 23.degree. C. in accordance with JIS K
6854-2 using a tabletop precision universal tester (Shimadzu
Corporation; AGS-X), and the adhesive strength of the multilayer
film in the molded body was evaluated.
(Synthesis Example 1) [Thermoplastic Elastomer (A-1)]
[0200] 64 L of cyclohexane as a solvent, 0.20 L of sec-butyl
lithium (10 mass % cyclohexane solution) as an initiator and 0.3 L
of tetrahydrofuran as an organic Lewis base were loaded into a
nitrogen-purged and dried pressure-resistant container. The
temperature was raised to 50.degree. C., 2.3 L of styrene were
added and the mixture was polymerized for 3 hours, after which 23 L
of isoprene were added and the mixture was polymerized for 4 hours,
after which a further 2.3 L of styrene were added and the mixture
was polymerized for 3 hours. The resulting reaction solution was
poured into 80 L of methanol, and the precipitated solid was
filtered out and dried for 20 hours at 50.degree. C. to obtain a
triblock copolymer including polystyrene-polyisoprene-polystyrene.
Next, 10 kg of the polystyrene-polyisoprene-polystyrene triblock
copolymer were dissolved in 200 L of cyclohexane, palladium carbon
(palladium carrier: 5 mass %) was added as a hydrogenation catalyst
in the amount of 5 mass % of the copolymer, and the mixture was
reacted for 10 hours at 150.degree. C., hydrogen pressure 2 MPa.
This was left to cool and depressurize, the palladium carbon was
removed by filtration, and the filtrate was concentrated and then
vacuum dried to obtain a hydrogenate of a triblock copolymer
including polystyrene-polyisoprene-polystyrene (hereunder called
"thermoplastic elastomer (A-1)"). The resulting thermoplastic
elastomer (A-1) had a weight-average molecular weight of 107,000 a
styrene content of 21 mass %, a hydrogenation rate of 85%, a
molecular weight distribution of 1.04, and a total ratio of 60 mol
% of 1,2 binding and 3,4 binding in the polyisoprene blocks.
(Synthesis Example 2) [Polyvinyl Acetal Resin (B-1)]
[0201] 75 kg of n-butylaldehyde and 110 kg of 35% to 37%
hydrochloric acid were added to an aqueous solution of 100 kg of
polyvinyl alcohol resin with an average degree of polymerization of
500 and a degree of saponification of 99 mol %, and stirred to
perform acetalization, and the resin was precipitated. This was
washed by known methods until the pH was 6, suspended in a sodium
hydroxide aqueous solution and stirred as post-treatment was
performed, washed until the pH was 7 and dried until the volatile
component was 0.3% to obtain a polyvinyl acetal resin (B-1) with a
degree of acetalization of 80 mol %.
(Synthesis Example 3) [Polar Group-Containing Polypropylene-Based
Resin (B-2)]
[0202] 42 kg of polypropylene (Prime Polymer Co., Ltd.; Prime
Polyprop F327), 160 g of maleic anhydride and 42 g of
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane were melt kneaded with
a batch mixer at 180.degree. C. at a screw rotation rate of 40 rpm
to obtain a polar group-containing polypropylene-based resin (B-2).
The polar group-containing polypropylene-based resin (B-2) had an
MFR of 6 g/10 min at 230.degree. C., load 2.16 kg (21.18 N), a
maleic anhydride concentration of 0.3'' and a melting point of
138.degree. C. The maleic anhydride concentration is a value
obtained by titration using a methanol solution of potassium
hydroxide. The melting point is a value determined from the
endothermic peak of the differential scanning calorimetry curve as
measured at a ramp rate of 10.degree. C./min.
(Synthesis Example 4) [Methacrylate Resin (F-1)]
[0203] 0.1 mass parts of a polymerization initiator
(2,2'-azobis(2-methylpropyonitrile), hydrogen abstraction ability
1%, 1-hour half life temperature 83.degree. C.) and 0.28 mass parts
of a chain transfer agent (n-octyl mercaptan) were added to a
monomer mixture consisting of 95 mass parts of methyl methacrylate
and 5 mass parts of methyl acrylate, and dissolved to obtain a raw
material solution. Meanwhile, 100 mass parts of ion-exchange water,
0.03 mass parts of sodium sulfate and 0.45 mass parts of a
suspending dispersant were mixed in a separate container to obtain
a mixed solution. 420 mass parts of the mixed solution and 210 mass
parts of the raw material solution were loaded into a
pressure-resistant polymerization tank, and stirred in a nitrogen
atmosphere as the temperature was raised to 70.degree. C. to
initiate a polymerization reaction. 3 hours after the start of the
polymerization reaction the temperature was raised to 90.degree.
C., and stirring was continued for 1 hour to obtain a solution of a
dispersed copolymer in bead form. The resulting copolymer
dispersion was washed with a suitable amount of ion-exchange water,
and the copolymer beads were extracted with a bucket-type
centrifuge and dried for 12 hours in an 80.degree. C. hot air drier
to obtain a methacrylic resin (F-1) in bead form with a
weight-average molecular weight Mw(F) of 30,000 and a Tg of
128.degree. C.
(Synthesis Example 5) [Block Copolymer (G-1)]
[0204] 735 kg of dry toluene. 39.4 kg of a toluene solution
containing 0.4 kg of hexamethyltriethylenetetramine and 20 mol of
isobutylbis(2,6-di-tert-butyl-4-methylphenoxy) aluminum, 1.17 mol
of sec-butyl lithium and 35.0 kg of methyl methacrylate were added
in that order at room temperature to a reaction vessel the interior
of which had been deaerated and nitrogen purged, and reacted for 1
hour at room temperature. Part of the reaction solution was
sampled, and the polymer contained in the reaction solution was
found to have a weight-average molecular weight of 40,000,
corresponding to the weight-average molecular weight Mw(g1-1) of
the methyl methacrylate polymer block (g1-1).
[0205] This reaction solution was then cooled to -25.degree. C.,
and a mixture of 24.5 kg of n-butyl acrylate and 10.5 kg of benzyl
acrylate was added dropwise over the course of 0.5 hours. Part of
the reaction solution was sampled, and the polymer contained
therein was found to have a weight-average molecular weight of
80,000. Since the weight-average molecular weight Mw(g1-1) of the
methyl methacrylate polymer block (g1-1) was 40,000, the
weight-average molecular weight Mw(g2) of the acrylic ester polymer
block (g2) consisting of a copolymer of n-butyl acrylate and benzyl
acrylate was determined to be 40,000.
[0206] 35.0 kg of methyl methacrylate were then added, and the
reaction solution was returned to room temperature and stirred for
8 hours to form a second methacrylic ester polymer block (g1-2). 4
kg of methanol were then added to the reaction solution to stop
polymerization, after which the reaction solution was poured into a
large quantity of methanol, and the filtrate was dried for 12 hours
at 80.degree. C., 1 torr (about 133 Pa) to isolate a block
copolymer (G-1). Since the weight-average molecular weight Mw(G) of
the resulting block copolymer (G-1) was 120,000, the weight-average
molecular weight Mw(g1-2) of the methyl methacrylate polymer block
(g1-2) was determined to be 40,000. Since the weight-average
molecular weight Mw(g1-1) of the methyl methacrylate polymer block
(g1-1) and the weight-average molecular weight Mw(g1-2) of the
methyl methacrylate polymer block (g1-2) are both 40,000, the
Mw(g1-total) is 80,000.
(Synthesis Example 6) [Block Copolymer (G-2)]
[0207] 1,040 g of dry toluene, 10 g of 1,2-dimethoxyethane 45 g of
a toluene solution containing mmol of
isobutylbis(2,6-di-tert-butyl-4-methylphenoxy)aluminum, 7.3 mmol of
sec-butyl lithium and 64 g of methyl methacrylate were added in
that order to a vessel the interior of which had been deaerated,
and reacted for 1 hour at room temperature. The weight-average
molecular weight Mw(g1-1) of the polymer contained in the reaction
solution was 9,700.
[0208] This reaction solution was then cooled to -25.degree. C.,
and 184 g of n-butyl acrylate were added drop wise over the course
of 2 hours. The weight-average molecular weight of the polymer
contained in the reaction solution was 37,600. Since the
weight-average molecular weight Mw(g1-1) of the methyl methacrylate
polymer block was 9,700, the weight-average molecular weight Mw(g2)
of the acrylic ester polymer block consisting of n-butyl acrylate
was determined to be 27,900.
[0209] 161 g of methyl methacrylate were then added, and the
reaction solution was returned to room temperature and stirred for
8 hours to form a second methacrylic ester polymer block. 4 g of
methanol was then added to the reaction solution to stop
polymerization, after which the reaction solution was poured into a
large quantity of methanol, and the filtrate was dried for 12 hours
at 80.degree. C., 1 torr to isolate a block copolymer (G-2). Since
the weight-average molecular weight of the resulting block
copolymer (G-2) was 62,000 the weight-average molecular weight
Mw(g1-2) of the methyl methacrylate polymer block was determined to
be 24,400. The ratio Mw/Mn of the weight-average molecular weight
to the number-average molecular weight of the block copolymer (G-2)
was 1.11.
(Synthesis Example 7) [Block Copolymer (G-3)]
[0210] 1,040 g of dry toluene, 10 g of 1,2-dimethoxyethane, 48 g of
a toluene solution containing 30 mmol of
isobutylbis(2,6-di-tert-butyl-4-methylphenoxy)aluminum, 8.1 mmol of
sec-butyl lithium and 72 g of methyl methacrylate were added in
that order to a vessel the interior of which had been deaerated,
and reacted for 1 hour at room temperature. The weight-average
molecular weight Mw(g1-1) of the polymer contained in the reaction
solution was 9,900.
[0211] This reaction solution was then cooled to -25.degree. C. and
307 g of n-butyl acrylate were added dropwise over the course of 2
hours. The weight-average molecular weight of the polymer contained
in the reaction solution was 32,300. Since the weight-average
molecular weight Mw(g1-1) of the methyl methacrylate polymer block
was 9,900, the weight-average molecular weight Mw(g2) of the
acrylic ester polymer block consisting of n-butyl acrylate was
determined to be 42,200.
[0212] 72 g of methyl methacrylate were then added, and the
reaction solution was returned to room temperature and stirred for
8 hours to form a second methacrylic ester polymer block. 4 g of
methanol was then added to the reaction solution to stop
polymerization, after which the reaction solution was poured into a
large quantity of methanol, and the filtrate was dried for 12 hours
at 80.degree. C., torr to isolate a block copolymer (G-3). Since
the weight-average molecular weight of the resulting block
copolymer (G-3) was 62,000, the weight-average molecular weight
Mw(g1-2) of the methyl methacrylate polymer block was determined to
be 9,900. The ratio Mw/Mn of the weight-average molecular weight to
the number-average molecular weight of the block copolymer (G-3)
was 1.19.
(Synthesis Example 8) [Multilayer Structure (E-1)]
[0213] 1,050 mass parts of ion-exchange water, 0.5 mass parts of
sodium dioctylsulfosuccinate and 0.7 mass parts of sodium carbonate
were loaded into a reaction vessel equipped with a stirrer a
thermometer a nitrogen gas introduction pipe, a monomer
introduction pipe and a reflux condenser, the interior of the
vessel was thoroughly purged with nitrogen gas, and the internal
temperature was then set 80.degree. C. 0.25 mass parts of potassium
persulfate were added to the mixture, which was then stirred for 5
minutes, after which 245 mass parts of a monomer mixture consisting
of a 94:5.8:0.2 mass ratio of methyl methacrylate:methyl
acrylate:allyl methacrylate were added continuously dropwise over
the course of 50 minutes, and after completion of dropping, the
polymerization reaction was continued for 30 minutes.
[0214] 0.32 mass parts of potassium peroxodisulfate were added to
the same reaction vessel and stirred for 5 minutes, after which 315
mass parts of a monomer mixture consisting of 80.6 mass % butyl
acrylate, 17.4 mass % styrene and 2 mass % allyl methacrylate were
added continuously dropwise over the course of 60 minutes, and
after completion of dropping, the polymerization reaction was
continued for 30 minutes.
[0215] Next 0.14 mass parts of potassium peroxidsulfate were added
to the same reaction vessel and stirred for 5 minutes, after which
140 mass parts of a monomer mixture consisting of a 94:6 mass ratio
of methyl methacrylate:methyl acrylate were supplied continuously
dropwise over the course of 30 minutes, and after completion of
dropping, the polymerization reaction was continued for 60 minutes
to obtain a multilayer structure (E-1).
(Manufacturing Example 1) [Thermoplastic Polymer Composition
(X-1)]
[0216] 100 mass parts of the thermoplastic elastomer (A-1) obtained
in Synthesis Example 1, 19 mass parts of the polyvinyl acetal resin
(B-1) obtained in Synthesis Example 2 and 25 mass parts of the
polar group-containing polypropylene-based resin (B-2) obtained in
Synthesis Example 3 were melt kneaded at 230.degree. C. in a
twin-screw extruder (here and in the following manufacturing
examples, Toshiba Machine Co., Ltd.; TEM-28), extruded in strands
and cut to manufacture pellets of a thermoplastic polymer
composition (X-1).
(Manufacturing Example 2) [Amorphous Resin (Y-1)]
[0217] 80 mass parts of the methacrylic resin (F-1) obtained in
Synthesis Example 4 and 20 mass parts of the block copolymer (G-1)
obtained in Synthesis Example 5 were melt kneaded at 230.degree. C.
with a twin-screw extruder, extruded in strands and cut to
manufacture pellets of an amorphous resin (Y'-1).
[0218] Next, 100 mass parts of this amorphous resin (Y'-1) and 2
mass parts of carbon black (Mitsubishi Chemical Corporation; #980)
were melt kneaded at 200.degree. C. with a twin-screw extruder,
extruded in strands and cut to obtain pellets of an amorphous resin
(Y-1) with a Tg of 126.degree. C.
(Manufacturing Example 3) [Amorphous resin (Y-2)]
[0219] Pellets of an amorphous resin (Y-2) with a Tg of 126.degree.
C. were obtained as in the Manufacturing Example 2 except that the
amount of the carbon black in Manufacturing Example 2 was changed
from 2 mass parts to 0.5 mass parts.
(Manufacturing Example 4) [Amorphous resin (Y-3)]
[0220] Pellets of an amorphous resin (Y-3) with a Tg of 126.degree.
C. were obtained as in Manufacturing Example 2 except that the
amount of the carbon black in Manufacturing Example 2 was changed
from 2 mass parts to 12 mass parts.
(Manufacturing Example 5) [Amorphous Resin (Y-4)]
[0221] 30 mass parts of a methacrylic resin (Kuraray Co., Ltd.,
Parapet HI0008, MFR 22 g/10 min at 230.degree. C. load 37.3 N), 50
mass parts of the block copolymer (G-2) obtained in Synthesis
Example 6, 20 mass parts of the block copolymer (G-3) obtained in
Synthesis Example 7 and 2 mass pans of carbon black (Mitsubishi
Chemical Corporation; #980) were melt kneaded at 230.degree. C.
with a twin-screw extruder, extruded in strands and cut to obtain
pellets of an amorphous resin (Y-4) with a Tg of 125.degree. C.
(Manufacturing Example 6) [Amorphous Resin (Y-5)]
[0222] 88 mass parts of the methacrylic resin (F-1), 12 mass parts
of the multilayer structure (E-1) and 2 mass path of carbon black
(Mitsubishi Chemical Corporation; #980) were melt kneaded at
230.degree. C. with a twin-screw extruder, extruded in strands and
cut to obtain pellets of an amorphous resin (Y-5) with a Tg of
129.degree. C.
(Manufacturing Example 7) [Amorphous Resin (Y-6)]
[0223] Pellets of an amorphous resin (Y-6) with a Tg of 129.degree.
C. were obtained as in Manufacturing Example 6 except that the 88
mass parts of the methacrylic resin (F-1) in Manufacturing Example
6 were changed to 80 mass parts, and the 12 mass parts of the
multilayer structure (E-1) were changed to 20 mass parts.
(Manufacturing Example 8) [Amorphous Resin (Y-7)]
[0224] Pellets of an amorphous resin (Y-7) with a Tg of 129.degree.
C. were obtained as in Manufacturing Example 6 except that the 88
mass parts of the methacrylic resin (F-1) in Manufacturing Example
6 were changed to 72 mass parts, and the 12 mass parts of the
multilayer structure (E-1) were changed to 28 mass parts.
(Manufacturing Example 9) [Amorphous Resin (Y-8)]
[0225] 100 mass parts of polyethylene terephthalate (Kuraray Co.,
Ltd. Kurapet KS760K) and 2 mass parts of Carbon Black (Mitsubishi
Chemical Corporation; #980) were melt kneaded at 230.degree. C.
with a twin-screw extruder, extruded in strands and cut to obtain
pellets of an amorphous resin (Y-8) with a Tg of 75.degree. C.
Example 1
[0226] Pellets of the thermoplastic polymer composition (X-1)
obtained in Manufacturing Example 1 and pellets of the amorphous
resin (Y-1) obtained in Manufacturing Example 2 were each loaded
into a hopper of a single-screw extruder (G.M Engineering;
VGM25-28EX), and co-extruded with a multi-manifold die to obtain a
multilayer film 30 cm wide and 250 .mu.m thick. The thickness of
each layer was controlled by means of the extension flow volume,
and the adhesive layer was 100 .mu.m thick while the base layer was
150 .mu.m thick. The evaluation results for the resulting
multilayer film are shown in Table 1.
[0227] Next, a molded body was manufactured from the resulting
multilayer film. That is, TOM forming was performed using a forming
machine (Fu-se Vacuum Forming Ltd.; NGF-0406-T) that forms a
chamber box (C) by closing a chamber box (C1) and a chamber box
(C2). A sheet-shaped adherend (length 150 mm.times.width 25
mm.times.thickness 0.3 mm) made of polypropylene resin (Japan
Polypropylene Corporation, MA03) was placed together with the
resulting multilayer film in the chamber box (C2) of the forming
machine with the adhesive layer of the multilayer film facing the
adherend, the multilayer film was sandwiched between the chamber
box (C1) and chamber box (C2) so that the multilayer film bisected
the chamber box (C), and the chamber box (C1) and chamber box (C2)
were closed to form the chamber box (C). The chamber box (C) was
then depressurized to 0.5 kPa over the course of 90 seconds.
Because the non-equilibrium of depressurization and the weight of
the multilayer film itself can cause the multilayer film to warp,
the pressures inside the chamber box (C1) and chamber box (C2) were
adjusted appropriately to keep the multilayer film level. During
depressurization the multilayer film was also heated for 120
seconds with an infrared heating device, and once the temperature
of the mull slayer film had reached 130.degree. C. the interior of
the chamber box (C1) was immediately returned to atmospheric
pressure to thereby overlay the adherend with the multilayer film
and form a molded body including the multilayer film adhering to
the adherend without elongation. The temperature of the multilayer
film was measured with a radiation thermometer. The chamber box (C)
was then opened and the molded bock was removed from the chamber
box (C2). The evaluation results for the resulting molded body are
shown in Table 1.
[0228] A molded body including the multilayer film adhering to the
adherend without elongation was also manufactured by the same
molded body manufacturing method except that a convex metal mold
(length 250 mm.times.width 160 mm.times.depth 25 mm) was placed
together with the adherend in the chamber box (C2), and the
adherend was set in the bottom of this metal mold. The evaluation
results for the resulting molded body are shown in Table 1.
Examples 2 to 6
[0229] Multilayer films and molded bodies were obtained as in
Example 1 except that the thicknesses of the adhesive layers and
multilayer films were changed as shown in Table 1.
Examples 7 and 8
[0230] Multilayer films and molded bodies were obtained as in
Example 1 except that the thicknesses of the base layers and
multilayer films were changed as shown in Table 1.
Examples 9 to 12
[0231] Multilayer films and molded bodies were obtained as in
Example 1 except that the amorphous resin (Y-1) was changed as
shown in Table 1.
Comparative Example 1
[0232] A multilayer film was obtained as in Example 1 except that
the thickness of the base layer in Example 1 was changed from 150
.mu.in to 600 .mu.m, and the thickness of the multilayer film was
changed from 250 .mu.in to 700 .mu.m. When the resulting multilayer
film was subjected to TOM forming as in Example 1, a molded body
was obtained including the multilayer film adhering to the adherend
without elongation, but when a convex metal mold was placed in the
chamber box (C2) together with the adherend and the adherend was
set in the bottom of the mold to create conditions that stretched
the film, the multilayer film broke at all temperatures between
110.degree. C. and 160.degree. C., and molded bodies were not
obtained.
Comparative Example 2
[0233] A multilayer film was obtained as in Example 1 except that
the amorphous resin (Y-3) obtained in Manufacturing Example 4 was
substituted for the amorphous resin (Y-1) of Example 1. When the
resulting multilayer film was subjected to TOM forming as in
Example 1, a molded body was obtained including fee multilayer film
adhering to the adherend without elongation, but when a convex
metal mold, was placed in the chamber box (C2) together with the
adherend and the adherend was set in the bottom of the mold to
create conditions that stretched the film, the multilayer film
broke at all temperatures between 110.degree. C. and 160.degree.
C., and molded bodies were not obtained.
Comparative Example 3
[0234] A multilayer film was obtained as in Example 1 except that
the amorphous resin (Y-4) obtained in Manufacturing Example 5 was
substituted for the amorphous resin (Y-1) of Example 1. When the
resulting multilayer film was subjected to TOM forming as in
Example 1, molded bodies including the multilayer film adhering to
the adherend without elongation was obtained at all temperatures
between 110.degree. C. and 160.degree. C. Molded bodies including
the multilayer film adhering to the adherend with elongation were
obtained without difficulty at 110.degree. C. to 140.degree. C.,
but at 150.degree. C. and 160.degree. C. the multilayer film
drooped and multiple wrinkles occurred in the molded body.
Comparative Example 4
[0235] A multilayer film was obtained as in Example 1 except that
the amorphous resin (Y-8) obtained in Manufacturing Example 9 was
substituted for the amorphous resin (Y-1) of Example 1. When the
resulting multilayer film was subjected to TOM forming as in
Example 1, a molded body was obtained including the multilayer film
adhering to the adherend without elongation, but when a convex
metal mold was placed in the chamber box (C2) together with the
adherend and the adherend was set in the bottom of the mold to
create conditions that stretched the film, the multilayer film
broke at all temperatures between 110.degree. C. and 160.degree.
C., and molded bodies were not obtained.
TABLE-US-00001 TABLE 1 Exam- Exam- Exam- Exam- Exam- Exam- Exam-
Exam- Exam- ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9
Base layer (amorphous resin) (Y-1): Manufacturing Example 2
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. (Y-2):
Manufacturing Example 3 .largecircle. (Y-3): Manufacturing Example
4 (Y-4): Manufacturing Example 5 (Y-5): Manufacturing Example 6
(Y-6): Manufacturing Example 7 (Y-7): Manufacturing Example 8
(Y-8): Manufacturing Example 9 Elastic modulus (110.degree. C.)
[MPa] 593 593 593 593 593 593 593 593 585 Elastic modulus
(160.degree. C.) [MPa] 2 2 2 2 2 2 2 2 2 Thickness of base layer
[.mu.m] 150 150 150 150 150 150 80 300 150 Adhesive layer
(thermoplastic polymer composition (X-1)) Thickness of adhesive
layer [.mu.m] 100 70 30 10 200 800 100 100 100 Physical properties
evaluation of multilayer film Thickness ratio (base layer/adhesive
layer) 1.5 2.1 5.0 15.0 0.8 0.2 0.8 3.0 1.5 Elongation at break[%]
200 200 200 200 200 200 200 160 250 Pencil hardness on base layer
side H H H H B 4B B H H Shielding A+ A+ A+ A+ A+ A+ A A+ A
Three-dimensional covering formability A A A A A A A A A PP
adhesive strength[N/25 mm] 48 45 40 38 >50 >50 48 48 48 PP
adhesive strength 21 20 18 15 26 >50 21 21 21 (with
elongation)[N/25 mm] Compar- Compar- Compar- Compar- ative ative
ative ative Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple 10 ple 11
ple 12 ple 1 ple 2 ple 3 ple 4 Base layer (amorphous resin) (Y-1):
Manufacturing Example 2 .largecircle. (Y-2): Manufacturing Example
3 (Y-3): Manufacturing Example 4 .largecircle. (Y-4): Manufacturing
Example 5 .largecircle. (Y-5): Manufacturing Example 6
.largecircle. (Y-6): Manufacturing Example 7 .largecircle. (Y-7):
Manufacturing Example 8 .largecircle. (Y-8): Manufacturing Example
9 .largecircle. Elastic modulus (110.degree. C.) [MPa] 575 551 432
593 645 195 471 Elastic modulus (160.degree. C.) [MPa] 2 2 2 2 2 1
140 Thickness of base layer [.mu.m] 150 150 150 600 150 150 150
Adhesive layer (thermoplastic polymer composition (X-1)) Thickness
of adhesive layer [.mu.m] 100 100 100 100 100 100 100 Physical
properties evaluation of multilayer film Thickness ratio (base
layer/adhesive layer) 1.5 1.5 1.5 6.0 1.5 1.5 1.5 Elongation at
break[%] 260 280 300 100 140 >300 150 Pencil hardness on base
layer side H H H H H 6B H Shielding A+ A+ A+ A+ A+ A+ A+
Three-dimensional covering formability A A A B B B B PP adhesive
strength[N/25 mm] 48 48 48 48 48 48 48 PP adhesive strength 21 21
21 -- -- 21 -- (with elongation)[N/25 mm]
[0236] The results of Table 1 show that the multilayer films
obtained in Examples 1 to 12 had excellent extensibility, shielding
properties, three-dimensional overlaying formability and
adhesiveness. In Examples 1 to 3 and 5 to 12, the adhesive strength
was high because the thermoplastic polymer composition forming the
adhesive layer was thick. In Comparative Examples 1, 2 and 4,
extensibility was low, the film broke during TOM forming and
formability was poor, in Comparative Example 3, because the elastic
modulus was low at high temperatures, the film drooped and wrinkled
during TOM forming at 150.degree. C. and above.
Reference Example 1
[0237] The elastic modulus of the base material obtained in
Manufacturing Example 2 was 1 MPa at 170.degree. C. When TOM
forming was performed as in Example 1 except that the heating
temperature of the multilayer film was changed from 130.degree. C.
to 170.degree. C., the multilayer film drooped and multiple
wrinkles appeared in the molded body.
Reference Example 2
[0238] The elastic modulus of the base material obtained in
Manufacturing Example 2 at 100.degree. C. was 1,010 MPa. When TOM
forming was performed as in Example 1 except that the heating
temperature of the multilayer film was changed from 130.degree. C.
to 100.degree. C., a molded body including the multilayer film
adhering to the adherend without elongation was obtained but when a
convex metal mold was placed in the chamber box (C2) together with
the adherend and the adherend was set in the bottom of the mold to
create conditions that stretched the film, the multilayer film
broke and a molded body was not obtained.
* * * * *